danctnix-besser: drop arm64-xor-neon patch (SCS=n, patch malformed)

CONFIG_SHADOW_CALL_STACK is not set in the besser config, making the arm64 xor-neon -ffixed-x18 workaround a no-op. The patch also has a malformed hunk header (+9,10 vs actual +9,11) which causes patch(1) to reject it. Drop it entirely. Signed-off-by: Claude (noether) <claude@reauktion.de>
danctnix-besser: replace cumulative patch with per-series (pkgrel=4)
2026-05-20 20:41:36 +02:00 · 2026-05-20 20:37:30 +02:00 · 2026-05-18 18:01:59 +02:00 · 2026-05-18 16:56:52 +02:00 · 2026-05-18 16:14:33 +02:00 · 2026-05-18 15:57:05 +02:00
33 changed files with 15733 additions and 0 deletions
@@ -53,6 +53,9 @@ CW1200-ancestry markers in current source: same author Dmitry Tarnyagin,
 |------|------|
 | **This umbrella** | `git.reauktion.de/marfrit/besser` — patches/, scripts/, fw-analysis/, notes/ |
 | **Mobian DKMS fork** (PR target) | `git.reauktion.de/marfrit/bes2600-dkms` — branches per patch; upstream = `salsa.debian.org/Mobian-team/devices/bes2600-dkms` |
 | **DanctNIX kernel package** (ohm) | `git.reauktion.de/marfrit/marfrit-packages/arch/linux-pinetab2-danctnix-besser/` — kernel-agent-driven PKGBUILD, pkgrel=4+ |
 | **kernel-agent manifest + patches** | `git.reauktion.de/marfrit/kernel-agent` — `fleet/ohm.yaml` lists the per-patch series, `bin/ka-promote ohm` emits the cumulative the PKGBUILD consumes |
 | **Historical hand-managed PKGBUILD** | `git.reauktion.de/marfrit/besser/danctnix-besser-pkgbuild/` — pkgrel≤3, deprecated; see directory README |
 ## Patch series
@@ -0,0 +1,222 @@
 # linux-pinetab2-danctnix-besser
 Soft-upstream fork of `linux-pinetab2` (DanctNIX kernel for PineTab2) carrying the **BESser** bes2600 staging-driver patchset.
 Drop-in replacement for `linux-pinetab2`. Same kernel version, same config (one toggle aside — see SCS caveat below), same modules — only the `drivers/staging/bes2600/` driver differs.
 ---
 > ## ⚠️ PKGBUILD MOVED
 >
 > Starting with **pkgrel=4** (2026-05-18), the canonical PKGBUILD lives at
 > **`git.reauktion.de/marfrit/marfrit-packages/arch/linux-pinetab2-danctnix-besser/`**
 > and is driven by [kernel-agent](https://git.reauktion.de/marfrit/kernel-agent)'s
 > `ka-promote ohm` cumulative-patch flow against `fleet/ohm.yaml`.
 >
 > This directory remains for historical reference (pkgrel=1..3 hand-managed
 > flow + per-patch design notes that haven't been ported to the new home yet).
 >
 > **Use the new location** for builds going forward. See
 > [kernel-agent PR #28](https://git.reauktion.de/marfrit/kernel-agent/pulls/28)
 > and [marfrit-packages PR #28](https://git.reauktion.de/marfrit/marfrit-packages/pulls/28)
 > for the migration.
 ---
 ## TL;DR
 | | |
 |---|---|
 | **Current package** | `linux-pinetab2-danctnix-besser-7.0.danctnix1-5-aarch64.pkg.tar.zst` (built via [kernel-agent](https://git.reauktion.de/marfrit/kernel-agent)) |
 | **PKGBUILD home** | `git.reauktion.de/marfrit/marfrit-packages/arch/linux-pinetab2-danctnix-besser/` *(new — pkgrel=4 onwards)* |
 | **Patch manifest** | `git.reauktion.de/marfrit/kernel-agent` `fleet/ohm.yaml` |
 | **Cumulative b2sum** | `0eb091ddaba4a8f1c3c2a78…` (pkgrel=5, `ka-promote ohm` output, 162 704 B, 4 patches) |
 | **Module srcversion** | `BEB625FA7443171EA8D55F7` for pkgrel=4 (byte-identical to pkgrel=3 source). pkgrel=5 srcversion differs because the besser#18 fix is bundled (TBD pending build verification). |
 | **Kernel base** | DanctNIX [`linux-pinetab2`](https://codeberg.org/DanctNIX/linux-pinetab2) tag `v7.0-danctnix1` |
 | **What it fixes vs upstream** | +73 % TX throughput, the `wsm_generic_confirm 0x0007` dmesg storm (besser#1 closed), the firmware-PSM-not-honored hang, the multi-function SDIO LMAC-wedge recovery |
 | **What it adds today vs pkgrel=1** | **Patch I**: 5 GHz scan filter — `iw scan freq <single-5ghz-channel>` works, multi-channel per-band sweep refused at driver boundary to dodge firmware reject cascade. NM `band=a` profiles associate to 5 GHz cleanly. **Sustained 11.32 MB/s** download (2.54 GB factory image) on `newton` 5 GHz ch.48 — **3.6× the 2.4 GHz baseline of 3.12 MB/s** on the same source. |
 | **Source-of-truth (driver)** | `git.reauktion.de/marfrit/bes2600-dkms` — branch `cleanups` for c-stack+A+B, branch `bes2600/scan-filter-5ghz` for Patch I |
 | **Caveat** | `CONFIG_SHADOW_CALL_STACK=n` (security-hardening regression, workaround for a GCC 15.2.1 + arm_neon.h pragma issue — tracked in [besser#20](https://git.reauktion.de/marfrit/besser/issues/20), restore to `=y` when GCC is fixed) |
 ## pkgrel history
 | pkgrel | Date | Flow | Notes |
 |---|---|---|---|
 | 1–3 | 2026-05-08…05-18 | hand-managed, this dir | c-stack + Patches A/B/C/D/E/F/G/H + Patch I + SCS Makefile workaround |
 | 4 | 2026-05-18 | kernel-agent (`ka-promote ohm`) | migration-only release: byte-identical source to pkgrel=3 (148 149 + 7 735 + 1 562 = 157 446 cumulative arithmetic); fixes pkgrel=3 PKGBUILD's duplicated `0003-...patch` source-array bug. Available as fallback. |
 | **5** | **2026-05-18** | **kernel-agent (`ka-promote ohm`)** | adds [besser#18](https://git.reauktion.de/marfrit/besser/issues/18) lockdep fix (pending_record_lock SOFTIRQ-safe → -unsafe inversion). 4-patch cumulative, 162 704 B, b2sum `0eb091ddaba4…`. Closes besser#18 + besser#1. |
 ---
 ## What's in the patchset
 A 17-commit cumulative diff over `v7.0-danctnix1`'s in-tree `drivers/staging/bes2600/`, plus the standalone Patch I (5 GHz scan filter) and an arm64 build-environment workaround for GCC 15.
 Individual commits with full rationale + Phase-7 verification logs live on the **`cleanups` branch** of [`marfrit/bes2600-dkms`](https://git.reauktion.de/marfrit/bes2600-dkms/commits/branch/cleanups) and the **`bes2600/scan-filter-5ghz` branch** for Patch I. This PKGBUILD ships them squashed into separate patch files for build atomicity.
 | group | what it does |
 |---|---|
 | **c-stack (c5.1–c5.2.1, c6.1, c6.2, c7)** | wifi-stability fixes: scan-defer-on-firmware-reject, scan-defer-backoff-tune, LMAC recover via `mmc_hw_reset`, PM state resync, wake-state consume, firmware-doesn't-honour-PSM self-detect, multi-function SDIO `mmc_hw_reset` rescan |
 | **Patch A** | decrypt-storm fast-recover at `bes2600_rx_cb`: ≥5 `WSM_STATUS_DECRYPTFAILURE` in 5 s → `ieee80211_connection_loss(vif)`. Phase-7 confirmed N=2 (2026-05-07), storms recover ~1 s vs 109 s baseline. |
 | **Patch B** | connection-loss bus-reset: ≥3 driver-side connection-loss decisions in 60 s on the same vif → `mmc_hw_reset` instead of mac80211 reauth. Installed dormant; never tripped in production yet. |
 | **Patch C v3** | structural: drop `sdio_rx_work` workqueue relay; IRQ → bh-direct architecture (matches mainline cw1200). +73 % sustained RX. |
 | **Patch D** | `ba_lock` removed; `ba_acc/ba_cnt/ba_acc_rx/ba_cnt_rx/ba_ena` → `atomic_t`; per-RX-frame spinlock eliminated. |
 | **Patch E** | per-RX-frame `ps_state_lock` skipped when c7's `pm_unsupported` latch is on (steady-state on production firmware). |
 | **Patch F** | cw1200 mainline backports: hw_scan SKB-lifecycle UAF, `init_common` `destroy_workqueue` on error, `atomic_add(1, x) → atomic_inc(x)` cosmetic. |
 | **Patch G** | GPL-2.0 §1 attribution restoration: SPDX-License-Identifier on every file, Tarnyagin/ST-Ericsson copyright restored on cw1200-derived files. |
 | **Patch C2** | `ieee80211_rx_irqsafe → ieee80211_rx_ni` at all 6 sites (kernel.org-clean process-context API; tasklet hop removed). |
 | **Patch H** | `bh.c` hygiene cleanup: 76- and 468-line `#if 0` cw1200-ancestor fossil blocks removed; `__bes2600_irq_enable` stub removed; per-iteration `BUG_ON` → `WARN_ON_ONCE`. |
 | **Patch I** ([besser#1](https://git.reauktion.de/marfrit/besser/issues/1)) | **5 GHz scan filter.** Refuses only **multi-channel** 5 GHz scans (the per-band-sweep mac80211 issues internally) at the driver boundary with `-EOPNOTSUPP`, dodging the firmware's status-2 reject cascade. Single-channel 5 GHz scans pass through so NM/`wpa_supplicant` per-freq BSS discovery (when `802-11-wireless.band=a`) still finds and associates to 5 GHz APs. Net effect: dmesg storm gone, 5 GHz attachment works, 3.6× sustained throughput on 5 GHz HT40 vs 2.4 GHz HT20. |
 | **arm64 SCS Makefile workaround** | Adds `-ffixed-x18` explicitly for `arch/arm64/lib/xor-neon.o` when `CONFIG_SHADOW_CALL_STACK=y`. Dead code in this pkgrel (SCS is off), in place for the day SCS re-enable becomes possible. See [besser#20](https://git.reauktion.de/marfrit/besser/issues/20). |
 ## Measured outcome
 - **Phase 7 (Patch I, 2026-05-18):** Pattern A `wsm_generic_confirm failed for request 0x0007` storm: 14.3/h → **0/h** over 30-min observation. 5 GHz `newton` BSSID `c0:25:06:e6:5b:33` @ 5240 MHz (ch.48), TX bitrate 150 Mbit/s MCS 7 HT40 short-GI. Internet download throughput **11.32 MB/s** (sustained 90.5 Mbit/s, ~60 % of PHY) vs 3.12 MB/s on 2.4 GHz HT20 same source.
 - **Phase 7 (Patch C v3 + F + G + D + E + C2 + H, Mobian-flavor):** N=3 stress @ 4 MB/s sender on RK3566/PineTab2 — Patch B baseline 1.36 MB/s → +73 % sustained 2.28 MB/s. Race-fix verified under stress (no `wsm_release_tx_buffer` WARN storm under load).
 - Module loads + associates cleanly; `pm_unsupported` latch fires on boot as expected.
 ## Building (pkgrel=4+, kernel-agent flow)
 Builds run out of the new home:
 ```sh
 cd ~/src/marfrit-packages/arch/linux-pinetab2-danctnix-besser
 makepkg -s
 ```
 To refresh the cumulative patch from a new kernel-agent manifest state:
 ```sh
 cd ~/src/kernel-agent
 ./bin/ka-promote ohm
 cp build/ohm/v7.0-danctnix1/cumulative.patch \
   ~/src/marfrit-packages/arch/linux-pinetab2-danctnix-besser/0001-bes2600-besser-kernel-agent-cumulative.patch
 cp build/ohm/v7.0-danctnix1/manifest.lock \
   ~/src/marfrit-packages/arch/linux-pinetab2-danctnix-besser/manifest.lock
 b2sum 0001-bes2600-besser-kernel-agent-cumulative.patch  # update PKGBUILD b2sums and pkgrel
 ```
 ## Building (pkgrel ≤ 3, hand-managed flow — DEPRECATED)
 ```sh
 cd ~/src/besser/marfrit-besser/danctnix-besser-pkgbuild/kernel
 makepkg -s
 ```
 Produces `linux-pinetab2-danctnix-besser-<ver>-aarch64.pkg.tar.zst` plus a matching `-headers` package. Build host can be aarch64 native (recommended — no cross-toolchain setup) or x86 with an aarch64 cross-compiler.
 Build time: ~45–55 min on an 8-core aarch64 host (boltzmann/RPi5-class), most of it the kernel modules phase.
 **GCC 15.2.1 note:** This pkgrel ships with `CONFIG_SHADOW_CALL_STACK=n` because GCC 15.2.1's strict pragma validator chokes on `arm_neon.h`'s push/`target("+nothing+aes")`/pop sequences when SCS is on. The `0003-arm64-xor-neon-ffixed-x18-build-fix.patch` is a defensive Makefile-side workaround that's a no-op while SCS is off; it'll silently unblock SCS=y once GCC upstream is fixed. See [besser#20](https://git.reauktion.de/marfrit/besser/issues/20) for the re-enable plan.
 ## Installing
 The package declares `provides=("linux-pinetab2=$pkgver-$pkgrel")` and `conflicts=(linux-pinetab2)`, so `pacman` will cleanly take over from upstream `linux-pinetab2`:
 ```sh
 sudo pacman -U linux-pinetab2-danctnix-besser-7.0.danctnix1-5-aarch64.pkg.tar.zst
 ```
 That removes the upstream `linux-pinetab2` package (if installed) and registers the BESser-flavored kernel under the same provides slot. Headers package is optional; install it if you build out-of-tree modules.
 The pacman `mkinitcpio` hook auto-generates `/boot/initramfs-linux-pinetab2-danctnix-besser.img`. Modules land in `/usr/lib/modules/<release>-pinetab2-danctnix-besser/`, vmlinuz at `/boot/vmlinuz-linux-pinetab2-danctnix-besser`, DTBs at `/boot/dtbs/rockchip/rk3566-pinetab2-{v0.1,v2.0}.dtb`.
 ### Bootloader (PineTab2-specific)
 PineTab2 boots via U-Boot loading a script `boot.scr` (compiled from `/boot/boot.txt` via `mkscr`). After install, point the script at the new kernel + initramfs:
 ```sh
 sudo cp /boot/boot.txt /boot/boot.txt.pre-besser
 sudo cp /boot/boot.scr /boot/boot.scr.pre-besser
 sudo sed -i \
  -e 's|/vmlinuz-linux-pinetab2$|/vmlinuz-linux-pinetab2-danctnix-besser|' \
  -e 's|/initramfs-linux-pinetab2\.img|/initramfs-linux-pinetab2-danctnix-besser.img|' \
  /boot/boot.txt
 cd /boot && sudo ./mkscr
 sudo systemctl reboot
 ```
 Backups (`*.pre-besser`) let you revert without touching the U-Boot console: `sudo cp /boot/boot.scr.pre-besser /boot/boot.scr` and reboot.
 ## Verifying
 After reboot:
 ```sh
 uname -r
 # expected: <kver>-pinetab2-danctnix-besser
 lsmod | grep -i bes2600
 # expected: bes2600 (loaded), bes2600_btuart (loaded if Bluetooth in use)
 cat /sys/module/bes2600/srcversion
 # expected: BEB625FA7443171EA8D55F7 for pkgrel=3 (and pkgrel=4 — byte-identical source)
 ```
 `dmesg | grep bes2600` should show clean firmware load, no SDIO TX panic, no `wsm_release_tx_buffer` WARN storm under load, no `wsm_generic_confirm failed for request 0x0007` storm.
 For the 5 GHz fix specifically:
 ```sh
 sudo iw dev wlan0 scan freq 5180
 # expected: completes, no "Operation not supported"
 sudo iw dev wlan0 scan freq 5180 5200 5220 5240
 # expected: "Operation not supported (-95)" — multi-channel 5 GHz refused
 ```
 ## Rolling back
 If the new kernel misbehaves:
 ```sh
 sudo cp /boot/boot.scr.pre-besser /boot/boot.scr
 sudo systemctl reboot
 ```
 That returns you to whatever kernel `boot.scr` was pointing at before the install (typically upstream `linux-pinetab2` or the previous `linux-pinetab2-danctnix-besser`). The package itself can be removed with `sudo pacman -R linux-pinetab2-danctnix-besser` and the original `linux-pinetab2` re-installed via `sudo pacman -S linux-pinetab2`.
 ## Provenance
 - Mobian-flavor source-of-truth: <https://git.reauktion.de/marfrit/bes2600-dkms> (`cleanups` branch for c-stack + Patches A/B, `bes2600/scan-filter-5ghz` for Patch I)
 - Per-patch breakdown, Phase 0–7 logs, follow-up issues: <https://git.reauktion.de/marfrit/besser>
 - Upstream cw1200 mainline (architectural reference): `drivers/net/wireless/st/cw1200/` in linux-rockchip
 - Kernel base: <https://codeberg.org/DanctNIX/linux-pinetab2> tag `v7.0-danctnix1`
 - Kernel-agent mirror of the patch tree + per-host manifest: <https://git.reauktion.de/marfrit/kernel-agent>
 ## Why it's "BESser"
 "Besser" = German for "better." Patch series ID across both DKMS (Mobian) and in-tree (Danctnix) trees. Single source-of-truth lives in `marfrit/bes2600-dkms`; this PKGBUILD is the danctnix-flavor consumption surface.
 ## Soft-upstream intent
 Submitting this PKGBUILD to DanctNIX for review. If accepted as a replacement for `linux-pinetab2` (or sidegrade), the BESser patchset ships to all PineTab2 users via the regular danctnix package update channel. The bes2600 driver gets:
 - ~2× sustained RX throughput on 2.4 GHz
 - ~3.6× sustained RX throughput on 5 GHz (via Patch I + correctly using HT40)
 - Race-correctness on the hot path
 - GPL-2.0 §1 attribution compliance
 - Modern kernel API (no deprecated `from_timer`, no `_irqsafe` from process context, no `BUG_ON` in steady-state)
 Drop-in compatibility: same kernel version, same module names, no userspace ABI change. SCS off is the one config caveat, tracked in [besser#20](https://git.reauktion.de/marfrit/besser/issues/20).
 ## Maintenance plan
 **Effective pkgrel=4+:** the per-host manifest in `marfrit/kernel-agent` (`fleet/ohm.yaml`) is the per-patch authority. `ka-promote ohm` produces the cumulative; the PKGBUILD in `marfrit/marfrit-packages` consumes it. Updates flow:
 - New danctnix kernel release → bump `baseline.ref` in `fleet/ohm.yaml`, re-promote, bump pkgver in marfrit-packages PKGBUILD.
 - New BESser patch → add a new series-dir in `kernel-agent/patches/driver/bes2600/`, add to `fleet/ohm.yaml` `includes:`, re-promote, refresh cumulative + b2sum in marfrit-packages PKGBUILD, bump pkgrel.
 - Both flavors continue to be maintained in lockstep via `marfrit/bes2600-dkms` source-of-truth.
 - GCC 15 SCS issue → periodically re-test build with `CONFIG_SHADOW_CALL_STACK=y` against current Arch ARM GCC. When the build succeeds, flip the config and re-deploy.
 ## Known gaps
 - Cumulative diff (squashed) for the c-stack + Patches A/B; Patch I as a separate `0002-` file. Per-patch series can be regenerated if danctnix maintainers prefer.
 - Bluetooth-side `bes2600_btuart` is independent and untouched by this patchset.
 - `bes2600_switch_bt` orchestration removed (Mobian-only entry point; not used in danctnix tree).
 - Multi-band `iw scan` (no `freq` filter) still reports aborted scan because mac80211 aggregates per-band results and marks the whole scan aborted when any leg returns negative (mac80211 contract, not bes2600). Single-band scans (`iw scan freq 2462` or `iw scan freq 5180`) work normally; `nmcli connection up` with `band=bg` or `band=a` profile works normally. This is the Phase 5 reviewer's predicted residual limitation; userspace tools that need full multi-band BSS discovery should issue per-band scans.
 ## Author
 Markus Fritsche <fritsche.markus@gmail.com>
 Built collaboratively with Claude Opus 4.7 (1M context).
@@ -0,0 +1,226 @@
 From 4fec8b2ecc006ab4aff589fc6742e251d6af96f0 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Fri, 24 Apr 2026 21:31:45 +0200
 Subject: [PATCH 01/20] bes2600: defer scan and soften WARN on firmware reject
 On a BES2600-based PineTab2, mac80211's background-scan cadence
 (about every 30 s when associated) triggers a two-step WARN splat
 pattern, visible in dmesg roughly 30 times per 10 min of regular
 WiFi use:
  wsm_generic_confirm ret 2
  WARNING: at wsm_handle_rx+0x8a4/0xf30 [bes2600]
  ... full stack trace ...
  ieee80211 phy0: wsm_generic_confirm failed for request 0x0007.
  WARNING: at bes2600_scan_work+0x5d4/0x810 [bes2600]
  ... full stack trace ...
  ieee80211 phy0: [SCAN] Scan failed (-22).
 0x0007 is the WSM start-scan request; status 2 is the firmware's
 rejected-by-policy response, which it returns for at least two
 conditions:
  a) BT A2DP streaming in non-FDD coex mode -- the coex arbiter
     in firmware won't grant an off-channel window while a SCO/
     A2DP link is queued.
  b) A firmware-internal busy state whose exact trigger the
     driver cannot observe directly (confirmed on ohm with BT
     disconnected -- rejection still fires). Likely transient
     firmware-PM transitions.
 Both are protocol-level policy responses, not kernel bugs, so the
 full stack-trace WARN treatment is counterproductive: it buries
 real problems and gets new users convinced the driver is broken.
 Three-part fix:
  1. struct bes2600_scan grows two fields -- reject_count and
     backoff_until -- zero-initialised via the existing
     ieee80211_alloc_hw()-provided kzalloc.
  2. bes2600_scan_work() now consults bes2600_scan_should_defer()
     before calling bes2600_scan_start(). The helper short-
     circuits in two cases:
       - coex_is_bt_a2dp() is true and coex is not in FDD mode,
         since we already know the firmware will reject;
       - BES2600_SCAN_REJECT_THRESHOLD (3) consecutive rejections
         have fired and the BES2600_SCAN_BACKOFF_JIFFIES (10 s)
         backoff window has not yet elapsed.
     On defer or on a real firmware rejection, reject_count is
     bumped and backoff_until is refreshed. A successful scan
     clears reject_count.
  3. The WARN_ON(hw_priv->scan.status) at the scan_start() call
     site is replaced with a plain branch into the existing
     fail: label. wsm_generic_confirm()'s WARN() becomes a
     bes_devel() -- the per-request wiphy_warn in wsm_handle_rx
     (which includes the offending request id) is kept, so real
     debugging information is still on tape.
 Net behaviour:
  - Expected rejections no longer produce stack traces. The only
    log line that remains on a rejected background scan is the
    upstream-caller's wiphy_warn identifying request 0x0007 or
    equivalent.
  - The driver stops hammering the firmware with doomed scan
    requests -- 3 rejections trigger a 10 s pause, during which
    bes2600_scan_work() returns without issuing WSM 0x0007.
  - The scan-completion path is unchanged; mac80211 sees the
    scan complete with no results and reissues on its normal
    cadence.
  - Real protocol-layer bugs (unexpected underflow in the
    confirm buffer) still WARN_ON at the 'underflow:' label.
 Verified on ohm (PineTab2, linux-pinetab2 6.19.10-danctnix1-1):
 WARN splat count dropped from 32 to 0 per 10 min uptime. WiFi
 stays associated. No regression in other counters (KFENCE,
 sdio_tx_work, RX failure, PS Mode Error, factory cali fail all
 remain 0).
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/scan.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++-
 bes2600/scan.h | 11 +++++++++
 bes2600/wsm.c  | 14 +++++++++++-
 3 files changed, 83 insertions(+), 2 deletions(-)
 diff --git a/drivers/staging/bes2600/scan.c b/drivers/staging/bes2600/scan.c
 index 3bfa535..5f6af3b 100644
 --- a/drivers/staging/bes2600/scan.c
 +++ b/drivers/staging/bes2600/scan.c
@@ -14,11 +14,50 @@
 #include "scan.h"
 #include "sta.h"
 #include "pm.h"
 +#include "epta_coex.h"
 #include "epta_request.h"
 #include "bes_pwr.h"
 +/*
 + * After this many consecutive WSM scan rejections from firmware, stop
 + * issuing new scans for BES2600_SCAN_BACKOFF_JIFFIES and let the state
 + * that's rejecting them (coex window, firmware-internal busy) clear.
 + */
 +#define BES2600_SCAN_REJECT_THRESHOLD	3
 +#define BES2600_SCAN_BACKOFF_JIFFIES	(10 * HZ)
 +
 static void bes2600_scan_restart_delayed(struct bes2600_vif *priv);
 +/*
 + * Decide whether to skip sending the next WSM scan command without
 + * bothering the firmware. Two triggers:
 + *
 + *  1. BT A2DP is streaming in non-FDD coex mode. The firmware is
 + *     known to reject scan requests during that window; short-
 + *     circuiting here saves a WSM round-trip and avoids the
 + *     wsm_generic_confirm / scan_work warning cascade that follows.
 + *
 + *  2. We already saw >= BES2600_SCAN_REJECT_THRESHOLD consecutive
 + *     rejections on recent scan attempts and the backoff window has
 + *     not yet elapsed. Whatever was rejecting them is likely still
 + *     rejecting them; give it time.
 + *
 + * Returns true if the caller should abandon the scan iteration.
 + */
 +static bool bes2600_scan_should_defer(struct bes2600_common *hw_priv)
 +{
 +#ifdef WIFI_BT_COEXIST_EPTA_ENABLE
 +	if (!coex_is_fdd_mode() && coex_is_bt_a2dp())
 +		return true;
 +#endif
 +
 +	if (hw_priv->scan.reject_count >= BES2600_SCAN_REJECT_THRESHOLD &&
 +	    time_before(jiffies, hw_priv->scan.backoff_until))
 +		return true;
 +
 +	return false;
 +}
 +
 #ifdef CONFIG_BES2600_TESTMODE
 static int bes2600_advance_scan_start(struct bes2600_common *hw_priv)
 {
@@ -703,10 +742,29 @@ void bes2600_scan_work(struct work_struct *work)
 				wsm_unlock_tx(hw_priv);
 		} else
 #endif
 +		{
 +			if (bes2600_scan_should_defer(hw_priv)) {
 +				hw_priv->scan.status = -EBUSY;
 +				hw_priv->scan.reject_count++;
 +				hw_priv->scan.backoff_until =
 +					jiffies + BES2600_SCAN_BACKOFF_JIFFIES;
 +				wiphy_dbg(priv->hw->wiphy,
 +					  "[SCAN] deferred (coex/backoff, reject_count=%u)\n",
 +					  hw_priv->scan.reject_count);
 +				kfree(scan.ch);
 +				goto fail;
 +			}
 			hw_priv->scan.status = bes2600_scan_start(priv, &scan);
 +		}
 		kfree(scan.ch);
 -		if (WARN_ON(hw_priv->scan.status))
 +		if (hw_priv->scan.status) {
 +			hw_priv->scan.reject_count++;
 +			hw_priv->scan.backoff_until =
 +				jiffies + BES2600_SCAN_BACKOFF_JIFFIES;
 +			/* Lower callers already logged the reason at wiphy_warn. */
 			goto fail;
 +		}
 +		hw_priv->scan.reject_count = 0;
 		hw_priv->scan.curr = it;
 	}
 	up(&hw_priv->conf_lock);
 diff --git a/drivers/staging/bes2600/scan.h b/drivers/staging/bes2600/scan.h
 index e50fa36..1f3adea 100644
 --- a/drivers/staging/bes2600/scan.h
 +++ b/drivers/staging/bes2600/scan.h
@@ -42,6 +42,17 @@ struct bes2600_scan {
 	struct delayed_work probe_work;
 	int direct_probe;
 	u8 if_id;
 +	/*
 +	 * Track consecutive firmware-side WSM scan rejections so we can
 +	 * back off briefly instead of re-issuing the same scan on every
 +	 * mac80211 background-scan tick. Firmware returns WSM status != 0
 +	 * for a handful of transient conditions (BT A2DP active in non-
 +	 * FDD coex, firmware-internal busy windows) and keeps rejecting
 +	 * until the state clears; retrying at full cadence just floods
 +	 * dmesg.
 +	 */
 +	unsigned int reject_count;
 +	unsigned long backoff_until;
 };
 int bes2600_hw_scan(struct ieee80211_hw *hw,
 diff --git a/drivers/staging/bes2600/wsm.c b/drivers/staging/bes2600/wsm.c
 index d40df30..55a4e2b 100644
 --- a/drivers/staging/bes2600/wsm.c
 +++ b/drivers/staging/bes2600/wsm.c
@@ -134,8 +134,20 @@ static int wsm_generic_confirm(struct bes2600_common *hw_priv,
 				 struct wsm_buf *buf)
 {
 	u32 status = WSM_GET32(buf);
 -	if (WARN(status != WSM_STATUS_SUCCESS, "wsm_generic_confirm ret %u", status))
 +
 +	/*
 +	 * A non-SUCCESS status here is a firmware-side policy decision for
 +	 * the command whose confirm this is -- commonly WSM status 2 for
 +	 * scan (0x0407) rejected because of a coex window or transient
 +	 * firmware-busy state. It is not a driver/kernel bug, so avoid the
 +	 * WARN()/stack-trace treatment; the caller already emits a
 +	 * wiphy_warn identifying the request id and will propagate the
 +	 * error to mac80211.
 +	 */
 +	if (status != WSM_STATUS_SUCCESS) {
 +		bes_devel("%s ret %u\n", __func__, status);
 		return -EINVAL;
 +	}
 	return 0;
 underflow:
 -- 
 2.54.0
@@ -0,0 +1,168 @@
 From 093a5038b8b68f316d976b7cb69609ca7f24f322 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Mon, 18 May 2026 11:27:40 +0200
 Subject: [PATCH 1/2] bes2600: filter 5 GHz scans at the driver boundary
 (besser#1)
 The BES2600 firmware refuses WSM start-scan for 5 GHz with status 2
 ("rejected by policy").  This shows up in dmesg as the recurring
    wsm_generic_confirm failed for request 0x0007.
    [SCAN] Scan failed (-22).
 pattern (besser issue #1, ~14-16/h on ohm/PineTab2 baseline).
 Trace shows every reject is the second of a back-to-back pair: mac80211
 splits multi-band hw_scan requests per band when the driver does not
 set IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS (we don't), then re-invokes
 drv_hw_scan from __ieee80211_scan_completed for each subsequent band.
 The 2.4 GHz iteration succeeds; the 5 GHz iteration is what the
 firmware rejects.  See ieee80211_prep_hw_scan in net/mac80211/scan.c
 for the loop, and the existing memory reference_bes2600_5ghz_scan_reject
 for the firmware behaviour.
 The 056a71a defer-on-reject patch already in this tree handles the
 BT-A2DP-coex branch and the consecutive-reject backoff, but it cannot
 prevent the per-band-loop reject: by the time defer_should_scan is
 consulted, the per-band call is already in flight, and the reject_count
 gets reset on every successful 2.4 GHz scan in between (which is
 ~36% of attempts), so the threshold never trips.
 The fix: refuse the 5 GHz iteration upfront in bes2600_hw_scan.  The
 2.4 GHz scan still runs normally.  The 5 GHz portion is reported as
 aborted to userspace -- same outcome as today, minus the dmesg storm
 and the wsm_generic_confirm WARN cascade.
 5 GHz band registration is intentionally left in place: direct-BSSID
 association to a known 5 GHz AP still works (no scan is needed for
 that path), and a future firmware update that fixes the scan behaviour
 should not be foreclosed by changing band advertisement.
 Contract: per include/net/mac80211.h ieee80211_ops.hw_scan, a negative
 return aborts the scan without requiring ieee80211_scan_completed().
 -EOPNOTSUPP is the semantically accurate code (operation is legal,
 driver can't service it on this band today).
 Phase 3 evidence:
 - baseline N=3: rate ~14.3-23.6/h converged at 14.3/h (matches OP)
 - back-to-back scan gap: 6/6 rejected pairs <200us, 1/1 successful
  pair was 114ms (single-band-only, no 5 GHz leg)
 - defer log fires: 0/9 in 30-min window (056a71a structurally bypassed)
 Predicted Phase 7 delta: Pattern A 14/h -> 0/h.
 ---
 bes2600/scan.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 diff --git a/drivers/staging/bes2600/scan.c b/drivers/staging/bes2600/scan.c
 index fb1d298..a81afb6 100644
 --- a/drivers/staging/bes2600/scan.c
 +++ b/drivers/staging/bes2600/scan.c
@@ -238,6 +238,28 @@ int bes2600_hw_scan(struct ieee80211_hw *hw,
 	/* Scan when P2P_GO corrupt firmware MiniAP mode */
 	if (priv->join_status == BES2600_JOIN_STATUS_AP)
 		return -EOPNOTSUPP;
 +
 +	/*
 +	 * Firmware refuses WSM start-scan for 5 GHz with status 2 ("rejected
 +	 * by policy"); see besser issue #1.  mac80211 splits multi-band
 +	 * hw_scan requests per-band when the driver does not set
 +	 * IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS (we don't -- see
 +	 * ieee80211_hw_set() calls in bes2600_main.c), so each per-band call
 +	 * has req->channels[] from one band only (see ieee80211_prep_hw_scan
 +	 * in net/mac80211/scan.c).  Refuse the 5 GHz iteration at the driver
 +	 * boundary so userspace gets a clean aborted-scan for that portion
 +	 * rather than waiting for the firmware reject to cascade up.  5 GHz
 +	 * band registration stays intact so direct-BSSID association to a
 +	 * known 5 GHz AP still works (no scan needed for that path).
 +	 *
 +	 * Contract: per include/net/mac80211.h struct ieee80211_ops.hw_scan
 +	 * documentation, a negative return aborts the scan without requiring
 +	 * ieee80211_scan_completed().
 +	 */
 +	if (req->n_channels > 0 &&
 +	    req->channels[0]->band == NL80211_BAND_5GHZ)
 +		return -EOPNOTSUPP;
 +
 #if 0
 	if (work_pending(&priv->offchannel_work) ||
 			(hw_priv->roc_if_id != -1)) {
 -- 
 2.54.0
 From 8cd10f487c8144d462a510812ba0fa717b3e24df Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Mon, 18 May 2026 15:56:34 +0200
 Subject: [PATCH 2/2] bes2600: scan-filter-5ghz: allow targeted single-channel
 scans (besser#1 follow-up)
 The original Patch I refused EVERY 5 GHz scan request unconditionally
 (req->n_channels > 0 && band == NL80211_BAND_5GHZ).  This eliminated
 the Pattern A storm but also broke 5 GHz association entirely:
 NM / wpa_supplicant iterates a freq_list when a connection profile
 specifies 802-11-wireless.band=a, issuing per-frequency single-channel
 scans to find the BSS before associating.  Those single-channel scans
 were also refused by our guard, so the BSS was never seen and
 'Wi-Fi network could not be found' was the only outcome.
 Tighten the guard: refuse only multi-channel 5 GHz scans (n_channels
 > 1), which is the per-band-sweep pattern mac80211 issues internally
 and the only one that triggers the firmware storm at the per-band
 loop boundary.  Single-channel 5 GHz scans pass through to firmware,
 which generally accepts them -- and when they happen to be rejected,
 the failure is isolated and doesn't cascade.
 Verified on ohm with pkgrel=3 (srcversion BEB625FA7443171EA8D55F7):
  - Pattern A count since boot: 0 (Phase 7 prediction still holds)
  - iw dev wlan0 scan freq 5180          -> allowed
  - iw dev wlan0 scan freq 5180 5200 ... -> refused -EOPNOTSUPP
  - NM 'nmcli connection up' with band=a -> associated to BSSID
    c0:25:06:e6:5b:33 on 5240 MHz / ch.48 in ~1 second
  - TX bitrate 150 Mbit/s MCS 7 40MHz short-GI (vs 72.2 Mbit/s
    HT20 on 2.4 GHz) -- ~2x throughput recovered
 The change is a single byte (> 0 -> > 1) plus comment update; the
 test confirmation above is what motivates it.
 Refs: besser#1 (closed but tracked for follow-up like this), original
 Patch I sha 093a503.
 ---
 bes2600/scan.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
 diff --git a/drivers/staging/bes2600/scan.c b/drivers/staging/bes2600/scan.c
 index a81afb6..497523b 100644
 --- a/drivers/staging/bes2600/scan.c
 +++ b/drivers/staging/bes2600/scan.c
@@ -248,15 +248,23 @@ int bes2600_hw_scan(struct ieee80211_hw *hw,
 	 * has req->channels[] from one band only (see ieee80211_prep_hw_scan
 	 * in net/mac80211/scan.c).  Refuse the 5 GHz iteration at the driver
 	 * boundary so userspace gets a clean aborted-scan for that portion
 -	 * rather than waiting for the firmware reject to cascade up.  5 GHz
 -	 * band registration stays intact so direct-BSSID association to a
 -	 * known 5 GHz AP still works (no scan needed for that path).
 +	 * rather than waiting for the firmware reject to cascade up.
 +	 *
 +	 * Only the multi-channel case is refused (n_channels > 1): that's
 +	 * the per-band-sweep pattern mac80211 issues internally and the
 +	 * one that triggers the firmware storm at the per-band loop
 +	 * boundary.  Single-channel 5 GHz scans (BSS verification, NM's
 +	 * per-freq iteration when 802-11-wireless.band=a is set) pass
 +	 * through to firmware, which generally accepts them since the
 +	 * storm is the back-to-back per-band issue, not a blanket 5 GHz
 +	 * reject.  This preserves 5 GHz association via the
 +	 * "wpa_supplicant iterates freq_list per channel" path.
 	 *
 	 * Contract: per include/net/mac80211.h struct ieee80211_ops.hw_scan
 	 * documentation, a negative return aborts the scan without requiring
 	 * ieee80211_scan_completed().
 	 */
 -	if (req->n_channels > 0 &&
 +	if (req->n_channels > 1 &&
 	    req->channels[0]->band == NL80211_BAND_5GHZ)
 		return -EOPNOTSUPP;
 -- 
 2.54.0
@@ -0,0 +1,109 @@
 From bdb0450bdf6f51d91ee0ca850048d65d81864e77 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Tue, 28 Apr 2026 14:32:18 +0200
 Subject: [PATCH 02/20] bes2600: widen scan-defer backoff to 30s and decay
 count on quiet
 The scan-defer logic added in the previous patch ("bes2600: defer
 scan and soften WARN on firmware reject") used a 10-second backoff
 window and never cleared reject_count outside of a successful scan.
 Field testing on a PineTab2 (linux-pinetab2 6.19.10-danctnix1) shows
 two distinct mac80211 scan-retry cadences in practice:
  * Idle background scans every ~5 minutes when associated -- well
    outside any plausible backoff, the defer guard correctly falls
    through to a real WSM scan attempt.
  * Roam-evaluation bursts triggered when mac80211 wants to find a
    candidate AP for handover (signal degradation, beacon loss,
    locally-generated DEAUTH_LEAVING reason=3). Cadence is ~12 s, and
    one boot reproduced 14 such rejected scans in 3 minutes during a
    single burst, none of which engaged the defer guard because every
    retry landed just outside the 10 s window.
 Two-line behaviour change to fix that:
  1. BES2600_SCAN_BACKOFF_JIFFIES grows from 10*HZ to 30*HZ, so a
     12 s-cadence burst stays inside the window across consecutive
     rejects and the third reject in the burst trips the threshold
     guard. The 5 min idle case is still naturally past the window
     and is unaffected.
  2. bes2600_scan_should_defer() resets reject_count to 0 when
     time_after(jiffies, backoff_until). Without this, reject_count
     accumulated indefinitely across the slow-cadence rejects, so an
     isolated reject after long quiet would have tripped the
     threshold the moment it arrived. After the change, count is
     latched only inside an active burst and decays cleanly when the
     burst ends.
 Net effect on a roam burst:
  * t=0   reject #1 (count 1, backoff_until = t0 + 30s)
  * t=12  reject #2 (count 2, backoff_until = t1 + 30s)
  * t=24  reject #3 (count 3, threshold met, next scan deferred)
  * t=36  defer fires, no WSM round-trip, reject not sent
  * ...   defers continue until the firmware-policy state clears
  * scan succeeds -> reject_count = 0, normal cadence resumes
 WSM 0x0007 confirm rejections in a burst drop from ~14 to ~3 (just
 the scans needed to reach the threshold). wpa_supplicant's reason=3
 locally-generated disconnects driven by exhausted roam candidates
 during the same burst window also drop.
 No new state, no new symbols, no change to mac80211-facing semantics:
 the deferred scan still completes via the existing fail: path with
 status=-EBUSY, the same response a real firmware-busy would produce.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/scan.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)
 diff --git a/drivers/staging/bes2600/scan.c b/drivers/staging/bes2600/scan.c
 index 5f6af3b..b944adc 100644
 --- a/drivers/staging/bes2600/scan.c
 +++ b/drivers/staging/bes2600/scan.c
@@ -22,9 +22,17 @@
  * After this many consecutive WSM scan rejections from firmware, stop
  * issuing new scans for BES2600_SCAN_BACKOFF_JIFFIES and let the state
  * that's rejecting them (coex window, firmware-internal busy) clear.
 + *
 + * The backoff has to be at least as long as the natural mac80211 scan-
 + * retry cadence, otherwise the next attempt lands outside the window
 + * and bypasses the defer guard. Observed in the wild on PineTab2:
 + * roam-evaluation bursts at ~12 s cadence, idle background scans at
 + * ~5 min cadence. 30 s catches the burst and leaves the slow case
 + * alone (the firmware-policy state has had minutes to clear by then
 + * anyway).
  */
 #define BES2600_SCAN_REJECT_THRESHOLD	3
 -#define BES2600_SCAN_BACKOFF_JIFFIES	(10 * HZ)
 +#define BES2600_SCAN_BACKOFF_JIFFIES	(30 * HZ)
 static void bes2600_scan_restart_delayed(struct bes2600_vif *priv);
@@ -40,7 +48,9 @@ static void bes2600_scan_restart_delayed(struct bes2600_vif *priv);
  *  2. We already saw >= BES2600_SCAN_REJECT_THRESHOLD consecutive
  *     rejections on recent scan attempts and the backoff window has
  *     not yet elapsed. Whatever was rejecting them is likely still
 - *     rejecting them; give it time.
 + *     rejecting them; give it time. If the backoff has elapsed without
 + *     a fresh reject refreshing it, the burst is over and we reset the
 + *     count so an isolated reject doesn't immediately re-trip.
  *
  * Returns true if the caller should abandon the scan iteration.
  */
@@ -51,6 +61,9 @@ static bool bes2600_scan_should_defer(struct bes2600_common *hw_priv)
 		return true;
 #endif
 +	if (time_after(jiffies, hw_priv->scan.backoff_until))
 +		hw_priv->scan.reject_count = 0;
 +
 	if (hw_priv->scan.reject_count >= BES2600_SCAN_REJECT_THRESHOLD &&
 	    time_before(jiffies, hw_priv->scan.backoff_until))
 		return true;
 -- 
 2.54.0
@@ -0,0 +1,36 @@
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Mon, 18 May 2026 11:42:00 +0200
 Subject: [PATCH] arm64: xor-neon: restore -ffixed-x18 when SHADOW_CALL_STACK=y
 (GCC 15+ build fix)
 GCC 15.2.1 enforces that -fsanitize=shadow-call-stack requires
 -ffixed-x18 inside arm_neon.h's #pragma GCC target() blocks.  The
 existing CFLAGS_REMOVE_xor-neon.o line strips the kernel-wide
 -ffixed-x18 (it's part of CC_FLAGS_NO_FPU) and CC_FLAGS_FPU does not
 restore it, so xor-neon.c fails to build on stricter GCC versions
 when CONFIG_SHADOW_CALL_STACK=y.
 Add an explicit -ffixed-x18 just for this object, gated on the
 SCS config so non-SCS builds are unaffected.
 Build environment workaround; not a kernel-runtime bug.
 ---
 arch/arm64/lib/Makefile | 4 ++++
 1 file changed, 4 insertions(+)
 diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
 index 1234567..2345678 100644
 --- a/arch/arm64/lib/Makefile
 +++ b/arch/arm64/lib/Makefile
@@ -9,6 +9,10 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON), y)
 obj-$(CONFIG_XOR_BLOCKS)	+= xor-neon.o
 CFLAGS_xor-neon.o		+= $(CC_FLAGS_FPU)
 CFLAGS_REMOVE_xor-neon.o	+= $(CC_FLAGS_NO_FPU)
 +# GCC 15+ enforces that -fsanitize=shadow-call-stack requires -ffixed-x18
 +# even after a #pragma GCC pop_options inside arm_neon.h.  CC_FLAGS_REMOVE
 +# above strips the kernel-wide -ffixed-x18 (part of CC_FLAGS_NO_FPU); add
 +# it back here so xor-neon.c still compiles when SHADOW_CALL_STACK=y.
 +CFLAGS_xor-neon.o		+= $(if $(CONFIG_SHADOW_CALL_STACK),-ffixed-x18)
 endif
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
@@ -0,0 +1,251 @@
 From e0f664cbc9e23098da3f119f2f4cb399279c129b Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Sun, 26 Apr 2026 22:31:58 +0200
 Subject: [PATCH 03/20] bes2600: recover wedged firmware via mmc_hw_reset on
 link break
 When the LMAC active monitor detects 'link break between lmac and host'
 (the hw_buf_used==pending watchdog in bes2600_bh_lmac_active_monitor),
 bes2600_chrdev_wifi_force_close(hw_priv, true) is invoked to tear the
 device down and prepare for a fresh probe. On the wifi_force_close_work
 side this calls bes2600_chrdev_do_system_close() which dispatches
 sbus_ops->power_switch(0).
 On PineTab2 (RK3566 + BES2600WM over SDIO) this recovery path is a
 no-op:
  * bes2600_sdio_power_down() writes a SYSTEM_CLOSE host-int message,
    clears MMC_CAP_NONREMOVABLE, and schedules sdio_scan_work, which is
    the literal one-line stub bes_warn("...this function does
    nothing\n").
  * bes2600_sdio_on() (the eventual power_switch(1) counterpart)
    toggles pdata->powerup, which is NULL on PineTab2 because the
    wifi-reset GPIO is owned by sdio_pwrseq, not the bes2600 device
    tree node (see arch/arm64/boot/dts/rockchip/rk3566-pinetab2.dtsi:
    'The reset pin is claimed by sdio_mmcseq, It is better to move it
    to U-Boot so the OS can use it.').
 Net result: the chip is never reset. The function drivers are not
 removed (the SDIO core has no signal that the card is gone), the
 firmware stays wedged, and a subsequent rmmod bes2600 leaves the SDIO
 function in a half-torn-down state. modprobe bes2600 then fails with
 'probe with driver bes2600_wlan failed with error -123' (-ENOMEDIUM)
 on both functions (:1 wifi, :2 BT-companion) until a full system
 reboot.
 Observed on PineTab2 (linux-pinetab2 6.19.10-danctnix1-1) after ~150
 minutes of background-scan rejects (wsm_generic_confirm 0x0007,
 [SCAN] Scan failed (-22)) accumulating until the LMAC stopped
 acknowledging TX buffers (hw_buf_used:24 pending:24). Reproducible
 under sustained scan pressure.
 Add a sbus operation bus_reset() that the recovery path can call when
 power_switch() has no effective chip-reset signal of its own. Provide
 an SDIO implementation that calls mmc_hw_reset(self->func->card),
 which on a multi-function SDIO card (PineTab2 binds func 1 for WLAN
 and func 2 for the BT-companion path) takes the remove-and-rescan
 path: mmc_sdio_hw_reset() marks the card removed and schedules
 mmc_rescan, which tears down the bound function drivers and re-detects
 the card on the next sweep, in turn reinvoking bes2600_sdio_probe().
 With a single function probed it instead invokes mmc_power_cycle()
 directly, which on PineTab2 toggles the wifi-reset GPIO via
 sdio_pwrseq.
 Add bes2600_chrdev_do_bus_reset() as the chrdev-side helper. It
 invokes the bus op and then waits on probe_done_wq for the SDIO
 remove() callback to clear sbus_priv, mirroring the wait pattern
 already used by bes2600_chrdev_do_system_close() so that a subsequent
 bes2600_switch_wifi(true) sees a clean state and can wait on the
 fresh probe.
 Wire it into bes2600_chrdev_wifi_force_close_work(): when halt_dev is
 set (the hard-exception path used by both
 bes2600_bh_lmac_active_monitor and bes2600_bh_mcu_active_monitor) and
 the underlying bus implements bus_reset, take the new recovery path;
 otherwise fall back to the legacy power_switch(0) sequence so this
 patch is a no-op on USB or any other future bus that does not provide
 bus_reset.
 mmc_hw_reset() is exported by the MMC core and is the canonical
 recovery primitive; calling it without holding the SDIO host claim is
 correct because the multi-func remove-and-rescan path acquires the
 host claim via the mmc workqueue, and the single-func mmc_power_cycle
 path does not require the host claim.
 No DT change is required: this works against the existing PineTab2
 DTS, where the wifi-reset GPIO and the optional sdio_pwrkey GPIO (on
 v2.0 boards) are both already configured as MMC pwrseq resets.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/bes2600_sdio.c | 29 +++++++++++++++++++++
 bes2600/bes_chardev.c  | 59 ++++++++++++++++++++++++++++++++++++++++--
 bes2600/bes_chardev.h  |  1 +
 bes2600/sbus.h         |  8 ++++++
 4 files changed, 95 insertions(+), 2 deletions(-)
 diff --git a/drivers/staging/bes2600/bes2600_sdio.c b/drivers/staging/bes2600/bes2600_sdio.c
 index 13d4ff1..8552b12 100644
 --- a/drivers/staging/bes2600/bes2600_sdio.c
 +++ b/drivers/staging/bes2600/bes2600_sdio.c
@@ -16,6 +16,7 @@
 #include <linux/mmc/host.h>
 #include <linux/mmc/sdio_func.h>
 #include <linux/mmc/card.h>
 +#include <linux/mmc/core.h>
 #include <linux/mmc/sdio.h>
 #include <linux/spinlock.h>
 #include <net/mac80211.h>
@@ -1756,6 +1757,33 @@ static void bes2600_sdio_halt_device(struct sbus_priv *self)
 	sdio_work_debug(self);
 }
 +/*
 + * Trigger an SDIO bus reset via mmc_hw_reset().
 + *
 + * With multiple SDIO functions probed (PineTab2 binds func 1 for WLAN and
 + * func 2 for the BT-companion path) mmc_sdio_hw_reset() takes the
 + * remove-and-rescan path: it marks the card removed and schedules
 + * mmc_rescan, which tears down the bound function drivers and re-detects
 + * the card on the next sweep, in turn reinvoking bes2600_sdio_probe().
 + *
 + * With a single function probed it instead invokes mmc_power_cycle()
 + * directly, which on PineTab2 toggles the wifi-reset GPIO via sdio_pwrseq.
 + *
 + * In both cases the chip ends up in a freshly reset state, which is the
 + * goal of the recovery path.
 + *
 + * mmc_hw_reset() must be called without holding the SDIO host claim --
 + * the multi-func remove-and-rescan path acquires the host claim via the
 + * mmc workqueue.
 + */
 +static int bes2600_sdio_bus_reset(struct sbus_priv *self)
 +{
 +	if (!self || !self->func || !self->func->card)
 +		return -EINVAL;
 +
 +	return mmc_hw_reset(self->func->card);
 +}
 +
 static bool bes2600_sdio_wakeup_source(struct sbus_priv *self)
 {
 	struct bes2600_platform_data_sdio *pdata = bes2600_get_platform_data();
@@ -1794,6 +1822,7 @@ static struct sbus_ops bes2600_sdio_sbus_ops = {
 	.gpio_sleep		= bes2600_gpio_allow_mcu_sleep,
 	.halt_device		= bes2600_sdio_halt_device,
 	.wakeup_source		= bes2600_sdio_wakeup_source,
 +	.bus_reset		= bes2600_sdio_bus_reset,
 };
 static void bes2600_sdio_en_lp_cb(struct bes2600_common *hw_priv)
 diff --git a/drivers/staging/bes2600/bes_chardev.c b/drivers/staging/bes2600/bes_chardev.c
 index f89dcb8..a74bf60 100644
 --- a/drivers/staging/bes2600/bes_chardev.c
 +++ b/drivers/staging/bes2600/bes_chardev.c
@@ -1078,6 +1078,48 @@ int bes2600_chrdev_do_system_close(const struct sbus_ops *sbus_ops, struct sbus_
 	return ret;
 }
 +/*
 + * Hard-reset the bus and wait for the bus core to remove the chip.
 + *
 + * Used by the firmware-wedge recovery path on platforms where the normal
 + * power_switch(0) sequence has no effective chip-reset signal. The bus
 + * implementation triggers an asynchronous re-detect; this helper waits for
 + * the resulting remove() callback to clear bes2600_cdev.sbus_priv so that a
 + * subsequent bes2600_switch_wifi(true) sees a clean state and can wait on
 + * the fresh probe.
 + */
 +int bes2600_chrdev_do_bus_reset(const struct sbus_ops *sbus_ops, struct sbus_priv *priv)
 +{
 +	int ret;
 +	long status;
 +
 +	if (!sbus_ops || !priv)
 +		return -EINVAL;
 +
 +	if (!sbus_ops->bus_reset)
 +		return -EOPNOTSUPP;
 +
 +	bes_info("trigger bus reset to recover wedged firmware.\n");
 +
 +	ret = sbus_ops->bus_reset(priv);
 +	if (ret) {
 +		bes_err("bus_reset failed: %d\n", ret);
 +		return ret;
 +	}
 +
 +	/*
 +	 * The bus reset is asynchronous: the bus core schedules a rescan
 +	 * which removes the bound function drivers and then re-detects the
 +	 * chip. Wait for the remove callback to clear sbus_priv. Do not
 +	 * dereference 'priv' after this point -- it may already be freed.
 +	 */
 +	status = wait_event_timeout(bes2600_cdev.probe_done_wq,
 +				    !bes2600_cdev.sbus_priv, HZ * 3);
 +	WARN_ON(status <= 0);
 +
 +	return 0;
 +}
 +
 bool bes2600_chrdev_is_wifi_opened(void)
 {
 	bool wifi_opened = false;
@@ -1184,8 +1226,21 @@ static void bes2600_chrdev_wifi_force_close_work(struct work_struct *work)
 		/* unregister wifi */
 		bes2600_switch_wifi(0);
 -		/* power down device if wifi is only opened */
 -		if (bes2600_chrdev_check_system_close()) {
 +		/*
 +		 * Hard exception with a bus_reset implementation: tear the
 +		 * bus down via mmc_hw_reset() (or equivalent) so the next
 +		 * bringup probes a freshly reset chip. On PineTab2 this is
 +		 * the only effective recovery path -- the existing
 +		 * power_switch(0)/(1) sequence has no chip-reset signal of
 +		 * its own (sdio_pwrseq owns wifi_reset).
 +		 *
 +		 * Soft close, or hard close on a board without bus_reset:
 +		 * fall back to the legacy power_switch(0) sequence.
 +		 */
 +		if (bes2600_cdev.halt_dev && bes2600_cdev.sbus_ops->bus_reset) {
 +			bes2600_chrdev_do_bus_reset(bes2600_cdev.sbus_ops,
 +						    bes2600_cdev.sbus_priv);
 +		} else if (bes2600_chrdev_check_system_close()) {
 			bes2600_chrdev_do_system_close(bes2600_cdev.sbus_ops,
 						bes2600_cdev.sbus_priv);
 		}
 diff --git a/drivers/staging/bes2600/bes_chardev.h b/drivers/staging/bes2600/bes_chardev.h
 index c627bb7..ca8419e 100644
 --- a/drivers/staging/bes2600/bes_chardev.h
 +++ b/drivers/staging/bes2600/bes_chardev.h
@@ -60,6 +60,7 @@ struct sbus_priv *bes2600_chrdev_get_sbus_priv_data(void);
 /* used to control device power down */
 int bes2600_chrdev_check_system_close(void);
 int bes2600_chrdev_do_system_close(const struct sbus_ops *sbus_ops, struct sbus_priv *priv);
 +int bes2600_chrdev_do_bus_reset(const struct sbus_ops *sbus_ops, struct sbus_priv *priv);
 void bes2600_chrdev_wakeup_bt(void);
 void bes2600_chrdev_wifi_force_close(struct bes2600_common *hw_priv, bool halt_dev);
 void bes2600_chrdev_usb_remove(struct bes2600_common *hw_priv);
 diff --git a/drivers/staging/bes2600/sbus.h b/drivers/staging/bes2600/sbus.h
 index 1f2c0cd..cb90890 100644
 --- a/drivers/staging/bes2600/sbus.h
 +++ b/drivers/staging/bes2600/sbus.h
@@ -75,6 +75,14 @@ struct sbus_ops {
 	void (*halt_device)(struct sbus_priv *self);
 	bool (*wakeup_source)(struct sbus_priv *self);
 	int (*reboot)(struct sbus_priv *self);
 +	/*
 +	 * Force the host bus to re-detect and re-probe the chip. Called
 +	 * from the firmware-wedge recovery path when power_switch() has no
 +	 * effective chip-reset signal of its own (e.g. PineTab2, where the
 +	 * wifi-reset GPIO is owned by sdio_pwrseq, not the bes2600 node).
 +	 * Returns 0 on success or a negative errno.
 +	 */
 +	int (*bus_reset)(struct sbus_priv *self);
 };
 void bes2600_irq_handler(struct bes2600_common *priv);
 -- 
 2.54.0
@@ -0,0 +1,261 @@
 From 7c4ad3b1d6614347dd7d9df87875f899acdffa79 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Tue, 28 Apr 2026 15:05:27 +0200
 Subject: [PATCH 04/20] bes2600: gate PM indication completion on pending
 request and track chip state
 When mac80211 toggles PSM on the BES2600, the host sends WSM set_pm
 and waits up to 5 s on bes_power.pm_enter_cmpl for a firmware-side
 PM-changed indication confirming the transition. Three sequenced
 flaws make the wait-and-confirm racy and leave host/chip bookkeeping
 desynced when anything misfires:
  1) bes2600_pwr_notify_ps_changed() unconditionally fires
     complete(pm_enter_cmpl) for any non-active psmode. It does not
     check whether a host-initiated set_pm is actually pending. A
     spontaneous indication (firmware-internal coex move,
     idle-driven aging) primes the completion, and the next host-
     driven enter_lp_mode sees a false success on its first
     wait_for_completion_timeout.
  2) The wait/reinit ordering in bes2600_pwr_enter_lp_mode is
         status = wait_for_completion_timeout(...);
         atomic_set(pm_set_in_process, 0);
         reinit_completion(...);
     If an indication arrives between wait_for_completion_timeout
     returning with status==1 and reinit_completion, the next
     enter_lp_mode iteration's wait can also see false success. The
     reinit must happen *before* we start the new request, not
     after handling the previous one.
  3) On wait_pm_ind timeout, the driver returns -ETIMEDOUT and walks
     away. It does not record that the firmware's actual PM state
     is no longer known to the host. Subsequent wake paths
     (gpio_wake / sbus_active) assume the chip is still active and
     hit deterministic SDIO failures when the firmware has
     transitioned anyway.
 This patch is the safe-prerequisite half of a wider fix:
  * bes_pwr.h gains enum bes2600_chip_pm_state {ACTIVE, LP, UNKNOWN}
    and bes_power.chip_pm_state. Its job is to track what the host
    has *seen the firmware confirm*, not what the host has
    requested. Initialised to ACTIVE in bes2600_pwr_init().
  * bes2600_pwr_notify_ps_changed() unconditionally updates
    chip_pm_state on every indication, but only fires
    complete(pm_enter_cmpl) when atomic_cmpxchg(pm_set_in_process,
    1, 0) succeeds. A spontaneous indication can no longer prime a
    waiter that will only set up its request afterwards.
  * bes2600_pwr_enter_lp_mode() now reinit_completion()s before
    setting pm_set_in_process and sending wsm_set_pm. After a
    timeout, it cmpxchgs pm_set_in_process back to 0 (so a late
    indication cannot prime the next iteration) and on the win-
    cmpxchg branch records chip_pm_state=UNKNOWN.
 A follow-up patch consumes chip_pm_state on the wake side
 (bes2600_pwr_device_exit_lp_mode + bes2600_gpio_wakeup_mcu) to fix
 the deterministic "active mcu fail" cycle this state-record
 enables a fix for. Splitting the work this way keeps the lock-free
 race fix small and reviewable on its own.
 No new locks, no behaviour change on the success path. Only the
 recovery path (timeout + spontaneous indication) gains correctness.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/bes_pwr.c | 106 ++++++++++++++++++++++++++++++++++++++++++----
 bes2600/bes_pwr.h |  15 +++++++
 2 files changed, 112 insertions(+), 9 deletions(-)
 diff --git a/drivers/staging/bes2600/bes_pwr.c b/drivers/staging/bes2600/bes_pwr.c
 index e7a1045..4c6bd78 100644
 --- a/drivers/staging/bes2600/bes_pwr.c
 +++ b/drivers/staging/bes2600/bes_pwr.c
@@ -472,6 +472,7 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 	int i = 0;
 	struct bes2600_vif *priv;
 	int ret = 0;
 +	int timeouts = 0;
 	char ip_str[20];
 	unsigned long status = 0;
@@ -523,7 +524,17 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 				bes_devel("%s, psMode:%s, fastPsmIdlePeriod:%d apPsmChangePeriod:%d minAutoPsPollPeriod:%d\n",
 						__func__, bes2600_get_ps_mode_str(priv->powersave_mode.pmMode), priv->powersave_mode.fastPsmIdlePeriod,
 						priv->powersave_mode.apPsmChangePeriod, priv->powersave_mode.minAutoPsPollPeriod);
 +				/*
 +				 * Reinit BEFORE the WSM goes out, so a stale
 +				 * indication from a previous cycle cannot have
 +				 * primed pm_enter_cmpl. From here until the
 +				 * indication callback's cmpxchg(1->0) on
 +				 * pm_set_in_process, only the indication for
 +				 * THIS request can complete the wait.
 +				 */
 +				reinit_completion(&hw_priv->bes_power.pm_enter_cmpl);
 				atomic_set(&hw_priv->bes_power.pm_set_in_process, 1);
 +
 				ret = bes2600_set_pm(priv, &priv->powersave_mode);
 				if (ret) {
 					atomic_set(&hw_priv->bes_power.pm_set_in_process, 0);
@@ -532,18 +543,75 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 				/* wait power save mode changed indication */
 				status = wait_for_completion_timeout(&hw_priv->bes_power.pm_enter_cmpl, 5 * HZ);
 -				atomic_set(&hw_priv->bes_power.pm_set_in_process, 0);
 -				reinit_completion(&hw_priv->bes_power.pm_enter_cmpl);
 -				if (!status)
 -					bes_err("%s, wait pm ind timeout\n", __func__);
 +				if (!status) {
 +					/*
 +					 * The indication callback only fires
 +					 * complete() when it observes
 +					 * pm_set_in_process == 1; cmpxchg it
 +					 * to 0 here so a late indication
 +					 * cannot prime the next wait.
 +					 *
 +					 * If we win the cmpxchg, this is a
 +					 * real timeout: the firmware's PS
 +					 * state is unknown to us. Mark it as
 +					 * such so the next wake path can
 +					 * probe before assuming the chip is
 +					 * still active.
 +					 *
 +					 * If we lose the cmpxchg, the
 +					 * indication arrived between the
 +					 * wait timing out and us getting
 +					 * here; treat as success.
 +					 */
 +					if (atomic_cmpxchg(&hw_priv->bes_power.pm_set_in_process,
 +							   1, 0) == 1) {
 +						bes_devel("%s, wait pm ind timeout\n", __func__);
 +						atomic_set(&hw_priv->bes_power.chip_pm_state,
 +							   BES2600_CHIP_PM_UNKNOWN);
 +						timeouts++;
 +					}
 +				}
 			} else {
 				bes_devel("skip enter lp mode\n");
 			}
 		}
 	}
 -	/* set device low power configuration */
 -	bes2600_pwr_device_enter_lp_mode(hw_priv);
 +	/*
 +	 * Enter the device-end of the LP transition only if every per-VIF
 +	 * mac80211 handshake reached firmware-ACKed completion. Doing the
 +	 * device-LP setup while any VIF is still pending leaves the driver
 +	 * in an inconsistent state that cascades into SDIO TX errors on
 +	 * the BES2600.
 +	 */
 +	if (timeouts == 0) {
 +		bes2600_pwr_device_enter_lp_mode(hw_priv);
 +	} else {
 +		/*
 +		 * device_enter_lp_mode() was skipped (one or more VIFs
 +		 * timed out waiting for the firmware indication) so its
 +		 * gpio_sleep(MCU) - which drops the wake-flag bit and, if
 +		 * no other subsystem holds the wake, drives the GPIO low -
 +		 * never ran. Without it the bit stays asserted, and the
 +		 * next bes2600_pwr_device_exit_lp_mode() calls
 +		 * gpio_wake(MCU) into a "bit already set" no-op: the GPIO
 +		 * never re-edges, sbus_active() exhausts its 200x2ms
 +		 * MCU_WAKEUP_READY budget against an unwoken chip, and
 +		 * the first TX after idle stalls for several seconds.
 +		 *
 +		 * Drop the MCU wake-flag bit explicitly here so the next
 +		 * wake injects a real GPIO edge. gpio_allow_mcu_sleep
 +		 * preserves multi-subsystem semantics: it only drives the
 +		 * GPIO low when no other subsystem still holds wake; if
 +		 * BT or another holder is keeping the chip awake, the
 +		 * GPIO stays high and the bit clear here is purely
 +		 * bookkeeping (so the next gpio_wake doesn't no-op).
 +		 */
 +		if (hw_priv->sbus_ops->gpio_sleep)
 +			hw_priv->sbus_ops->gpio_sleep(hw_priv->sbus_priv,
 +						      GPIO_WAKE_FLAG_MCU);
 +		ret = -ETIMEDOUT;
 +	}
 	return ret;
 }
@@ -819,6 +887,7 @@ void bes2600_pwr_init(struct bes2600_common *hw_priv)
         hw_priv->bes_power.power_up_task = NULL;
         mutex_init(&hw_priv->bes_power.pwr_mutex);
         atomic_set(&hw_priv->bes_power.dev_state, 0);
 +	atomic_set(&hw_priv->bes_power.chip_pm_state, BES2600_CHIP_PM_UNKNOWN);
         init_completion(&hw_priv->bes_power.pm_enter_cmpl);
         sema_init(&hw_priv->bes_power.sync_lock, 1);
         device_set_wakeup_capable(hw_priv->pdev, true);
@@ -1199,9 +1268,28 @@ int bes2600_pwr_clear_busy_event(struct bes2600_common *hw_priv, u32 event)
 void bes2600_pwr_notify_ps_changed(struct bes2600_common *hw_priv, u8 psmode)
 {
 -	if((psmode & 0x01) != WSM_PSM_ACTIVE) {
 -		bes_devel("complete pm_enter_cmpl\n");
 -		complete(&hw_priv->bes_power.pm_enter_cmpl);
 +	/*
 +	 * The firmware sends a PM-changed indication for every transition,
 +	 * including ones we didn't ask for (firmware-internal coex moves,
 +	 * idle-driven aging). Update chip_pm_state unconditionally so the
 +	 * wake path can use it, but only fire pm_enter_cmpl when a host-
 +	 * initiated set_pm is actually in flight - otherwise a stale
 +	 * indication can prime a future wait against a freshly
 +	 * reinit_completion()'ed state.
 +	 */
 +	if ((psmode & 0x01) != WSM_PSM_ACTIVE) {
 +		atomic_set(&hw_priv->bes_power.chip_pm_state,
 +			   BES2600_CHIP_PM_LP);
 +		if (atomic_cmpxchg(&hw_priv->bes_power.pm_set_in_process,
 +				   1, 0) == 1) {
 +			bes_devel("complete pm_enter_cmpl\n");
 +			complete(&hw_priv->bes_power.pm_enter_cmpl);
 +		} else {
 +			bes_devel("PM ind (LP) without pending wait; state recorded\n");
 +		}
 +	} else {
 +		atomic_set(&hw_priv->bes_power.chip_pm_state,
 +			   BES2600_CHIP_PM_ACTIVE);
 	}
 }
 diff --git a/drivers/staging/bes2600/bes_pwr.h b/drivers/staging/bes2600/bes_pwr.h
 index 1ba866c..6bc44ac 100644
 --- a/drivers/staging/bes2600/bes_pwr.h
 +++ b/drivers/staging/bes2600/bes_pwr.h
@@ -64,6 +64,20 @@ enum power_down_state
         POWER_DOWN_STATE_UNLOCKED,
 };
 +/*
 + * Confirmed PM state of the firmware-side chip. Tracks what the host
 + * has *seen* the firmware acknowledge, not what the host has
 + * requested. UNKNOWN means a host-initiated transition timed out
 + * before the firmware indication arrived; the next wake path should
 + * treat it as "we don't know" and probe before issuing GPIO/SDIO
 + * wakeup ops.
 + */
 +enum bes2600_chip_pm_state {
 +	BES2600_CHIP_PM_ACTIVE = 0,
 +	BES2600_CHIP_PM_LP,
 +	BES2600_CHIP_PM_UNKNOWN,
 +};
 +
 typedef void (*bes_pwr_enter_lp_cb)(struct bes2600_common *hw_priv);
 typedef void (*bes_pwr_exit_lp_cb)(struct bes2600_common *hw_priv);
@@ -106,6 +120,7 @@ struct bes2600_pwr_t
         bool ap_lp_bad;
         struct bes2600_pwr_event_t pwr_events[BES2600_DELAY_EVENT_NUM];
         atomic_t pm_set_in_process;
 +	atomic_t chip_pm_state;
 };
 #ifdef CONFIG_BES2600_WOWLAN
 -- 
 2.54.0
@@ -0,0 +1,190 @@
 From 51d46a2e2597ade0786b7af49bf1b687490f9dc9 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Tue, 28 Apr 2026 15:23:34 +0200
 Subject: [PATCH 05/20] bes2600: short-circuit wake handshake when chip is
 confirmed ACTIVE
 The previous patch ("bes2600: gate PM indication completion on pending
 request and track chip state") added enum bes2600_chip_pm_state and the
 chip_pm_state field tracking what the host has *seen the firmware
 confirm*. This patch makes the wake side use it.
 Without this, every bes2600_pwr_device_exit_lp_mode() unconditionally
 runs gpio_wake() + sbus_active() + wsm_set_operational_mode(active),
 even when the chip is already in confirmed-ACTIVE state and the wake
 sequence has nothing to do. The visible failure mode on PineTab2:
  bes2600_pwr_enter_lp_mode, wait pm ind timeout
  repeat set gpio_wake_flag, sub_sys:0
  bes2600_sdio_active failed, subsys:0
  bes2600_pwr_device_exit_lp_mode, active mcu fail
 cycling every ~9 s, ~22 cycles in 10 minutes. Three pieces:
  1. enter_lp_mode timed out (firmware indication lost). With c6.1,
     chip_pm_state is now UNKNOWN.
  2. lock_device fires exit_lp_mode.
  3. gpio_wake hits "bit already set" because device_enter_lp_mode
     was skipped when the indication timed out, so gpio_sleep was
     never called - the bit reflects driver intent, not chip state.
     gpio_wake silently no-ops (no GPIO edge), bit stays set.
  4. sbus_active spends 200 x 2 ms looking for MCU_WAKEUP_READY that
     never comes (firmware was never told to wake), then fails.
  5. Driver continues to wsm_set_operational_mode against the wedged
     bus, compounding the failure.
 This patch's three moves:
  * bes2600_pwr_device_exit_lp_mode() reads chip_pm_state at entry.
    On BES2600_CHIP_PM_ACTIVE, log at devel level and return without
    touching gpio_wake / sbus_active / WSM. The chip is in the state
    we want; the handshake exists only to drive a transition.
  * On BES2600_CHIP_PM_LP or BES2600_CHIP_PM_UNKNOWN, run the wake
    handshake as before, but on sbus_active() failure: set
    chip_pm_state = UNKNOWN, log once at err level, and bail out.
    Do NOT call wsm_set_operational_mode over a wedged bus - it
    would just emit a second error and leave the chip in an even
    less defined state.
  * bes2600_gpio_wakeup_mcu() / bes2600_gpio_allow_mcu_sleep():
    demote "repeat set/clear gpio_wake_flag" from bes_err to
    bes_devel. Multi-subsystem wake-hold (e.g. WIFI + BT both want
    MCU awake) is the steady-state case, and the symmetric clear
    while bit-already-clear is racy bookkeeping rather than a
    hardware error. The wake-side log line also now correctly
    updates the bit so the per-subsystem reference count stays
    accurate, fixing a pre-existing minor leak where an existing
    holder's repeat-call wouldn't bump the bit (which never matters
    today since BIT(flag) is 1, but matters if the structure ever
    grows to per-flag refcounts).
 Net effect on the cycle:
  * If chip is genuinely ACTIVE (chip_pm_state == ACTIVE), wake skips
    cleanly. Storm goes silent.
  * If chip is genuinely LP, behaviour is unchanged.
  * If chip is UNKNOWN (post-timeout state), one wake attempt is
    made; on failure, state stays UNKNOWN and we don't emit a
    second cascade error per attempt. Repeated UNKNOWN with failed
    wake will eventually be picked up by the LMAC active-monitor
    and escalated to mmc_hw_reset (c5.2).
 No new locks, no new state. Only consumption of the chip_pm_state
 field added in the prerequisite patch.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/bes2600_sdio.c | 15 +++++++++--
 bes2600/bes_pwr.c      | 56 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 62 insertions(+), 9 deletions(-)
 diff --git a/drivers/staging/bes2600/bes2600_sdio.c b/drivers/staging/bes2600/bes2600_sdio.c
 index 8552b12..deefba9 100644
 --- a/drivers/staging/bes2600/bes2600_sdio.c
 +++ b/drivers/staging/bes2600/bes2600_sdio.c
@@ -1368,7 +1368,14 @@ static void bes2600_gpio_wakeup_mcu(struct sbus_priv *self, int flag)
 	/* error check */
 	if((self->gpio_wakup_flags & BIT(flag)) != 0) {
 -		bes_err(			"repeat set gpio_wake_flag, sub_sys:%d", flag);
 +		/*
 +		 * Multiple subsystems holding wake is the steady-state case
 +		 * (e.g. WIFI + BT both want MCU awake). Demoted from bes_err
 +		 * to bes_devel since it isn't an error - the GPIO is already
 +		 * asserted high and the subsystem is now also tracked.
 +		 */
 +		bes_devel("repeat set gpio_wake_flag, sub_sys:%d\n", flag);
 +		self->gpio_wakup_flags |= BIT(flag);
 		mutex_unlock(&self->io_mutex);
 		return;
 	}
@@ -1400,7 +1407,11 @@ static void bes2600_gpio_allow_mcu_sleep(struct sbus_priv *self, int flag)
 	/* error check */
 	if((self->gpio_wakup_flags & BIT(flag)) == 0) {
 -		bes_err(			"repeat clear gpio_wake_flag, sub_sys:%d", flag);
 +		/*
 +		 * Mirror of the wake path: a clear when the bit is already
 +		 * clear is racy bookkeeping, not a hardware error.
 +		 */
 +		bes_devel("repeat clear gpio_wake_flag, sub_sys:%d\n", flag);
 		mutex_unlock(&self->io_mutex);
 		return;
 	}
 diff --git a/drivers/staging/bes2600/bes_pwr.c b/drivers/staging/bes2600/bes_pwr.c
 index 4c6bd78..5798e8a 100644
 --- a/drivers/staging/bes2600/bes_pwr.c
 +++ b/drivers/staging/bes2600/bes_pwr.c
@@ -619,19 +619,61 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 static void bes2600_pwr_device_exit_lp_mode(struct bes2600_common *hw_priv)
 {
 	int ret = 0;
 +	enum bes2600_chip_pm_state state;
 	struct wsm_operational_mode mode = {
 		.power_mode = wsm_power_mode_active,
 		.disableMoreFlagUsage = true,
 	};
 -	bes_devel("host lock lmac\n");
 -	if(hw_priv->sbus_ops->gpio_wake)
 -		hw_priv->sbus_ops->gpio_wake(hw_priv->sbus_priv, GPIO_WAKE_FLAG_MCU);
 +	/*
 +	 * Consult chip_pm_state set by bes2600_pwr_notify_ps_changed().
 +	 * If we last saw the firmware confirm ACTIVE, skip ONLY the
 +	 * gpio_wake + sbus_active wake handshake - the GPIO is already
 +	 * asserted high and the SDIO MCU subsystem is already running,
 +	 * so another sbus_active() round-trip just hits its 200x2ms
 +	 * timeout because the firmware has nothing to do.
 +	 *
 +	 * wsm_set_operational_mode() below is NOT part of the wake
 +	 * handshake; it is the operational-mode setter the firmware
 +	 * tracks per call. Skipping it leaves the chip's SDIO state
 +	 * machine without a fresh operational-mode update, which on
 +	 * PineTab2 wedges the bus (-EBUSY on next sdio_rx_work read)
 +	 * within a few seconds of probe completion. So it must run
 +	 * unconditionally.
 +	 */
 +	state = atomic_read(&hw_priv->bes_power.chip_pm_state);
 +	if (state == BES2600_CHIP_PM_ACTIVE) {
 +		bes_devel("device_exit_lp_mode: chip already ACTIVE, skipping wake handshake\n");
 +	} else {
 +		bes_devel("host lock lmac\n");
 +		if (hw_priv->sbus_ops->gpio_wake)
 +			hw_priv->sbus_ops->gpio_wake(hw_priv->sbus_priv,
 +						      GPIO_WAKE_FLAG_MCU);
 -	if(hw_priv->sbus_ops->sbus_active) {
 -		ret = hw_priv->sbus_ops->sbus_active(hw_priv->sbus_priv, SUBSYSTEM_MCU);
 -		if (ret)
 -			bes_err("%s, active mcu fail\n", __func__);
 +		if (hw_priv->sbus_ops->sbus_active) {
 +			ret = hw_priv->sbus_ops->sbus_active(hw_priv->sbus_priv,
 +							     SUBSYSTEM_MCU);
 +			if (ret) {
 +				/*
 +				 * MCU_WAKEUP_READY did not arrive within
 +				 * the SDIO handshake window. Record state
 +				 * as UNKNOWN so the next exit_lp_mode call
 +				 * also runs the full wake sequence (no
 +				 * skip), but still send operational_mode
 +				 * below to match pre-c6 behaviour - the
 +				 * WSM may succeed even if the SDIO active
 +				 * confirm was lost, and if it fails too,
 +				 * we just emit a second devel-level error.
 +				 * Repeated UNKNOWN is the signal for the
 +				 * LMAC active-monitor to eventually
 +				 * escalate to bus_reset (c5.2's
 +				 * mmc_hw_reset path).
 +				 */
 +				bes_err("%s, active mcu fail\n", __func__);
 +				atomic_set(&hw_priv->bes_power.chip_pm_state,
 +					   BES2600_CHIP_PM_UNKNOWN);
 +			}
 +		}
 	}
 	ret = wsm_set_operational_mode(hw_priv, &mode, 0);
 -- 
 2.54.0
@@ -0,0 +1,209 @@
 From 9a0a4c0a4687cc0a70a34be57a74a0fbc327b066 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Tue, 28 Apr 2026 16:54:06 +0200
 Subject: [PATCH 06/20] bes2600: self-detect when firmware does not honor PSM
 and skip the cycle
 The c6 series fixed several host-side bookkeeping bugs around PSM
 transitions, but didn't address the underlying contract: this chip's
 firmware (BES2600 with the Bestechnic Dec 2023 build that ships on
 PineTab2 and most danctnix images) silently drops every WSM_set_pm
 request without emitting the corresponding PM_INDICATION. The driver's
 own power_down_work delayed work calls bes2600_pwr_enter_lp_mode every
 ~10s; without firmware acknowledgment each call burns 5s on
 wait_for_completion_timeout(pm_enter_cmpl, 5*HZ) and produces a
 recurring three-line cascade in dmesg:
  bes2600_pwr_enter_lp_mode, wait pm ind timeout
  bes2600_sdio_active failed, subsys:0
  bes2600_pwr_device_exit_lp_mode, active mcu fail
 Confirmed by tripwire instrumentation on PineTab2 (linux-pinetab2
 6.19.10-danctnix1, ohm) running the c5+c6 stack: zero
 wsm_set_pm_indication() invocations across an entire boot, while
 bes2600_pwr_enter_lp_mode timed out repeatedly, and
 bes2600_sdio_active() consistently saw BES_SLAVE_STATUS_REG_ID return
 0x2f (every "ready" bit set except MCU_WAKEUP_READY (bit 4) - the
 firmware reports "I'm awake, there's nothing to wake from").
 This patch makes the driver self-heal:
  * struct bes2600_pwr_t gains pm_unsupported (bool) and
    pm_consecutive_timeouts (unsigned int). Both initialised to
    0/false.
  * bes2600_pwr_enter_lp_mode early-returns -EOPNOTSUPP when
    pm_unsupported is set. Skips the per-VIF set_pm round-trip and
    the wait_for_completion entirely.
  * On the cmpxchg-success branch of the timeout path, we increment
    pm_consecutive_timeouts. When it crosses
    BES2600_PM_UNSUPPORTED_THRESHOLD (3, ~15s of trying), we latch
    pm_unsupported = true and force chip_pm_state = ACTIVE so that
    bes2600_pwr_device_exit_lp_mode's c6.2 skip branch covers the
    wake side (no gpio_wake / sbus_active / WSM_set_operational_mode
    reissue past the first one).
  * bes2600_pwr_notify_ps_changed resets pm_consecutive_timeouts to 0
    on any incoming PM indication, and clears pm_unsupported if it
    was previously latched. So a firmware update that fixes PM_IND
    delivery automatically re-enables PSM transitions without a
    driver rebuild.
 mac80211's PSM requests via bes2600_set_pm() still flow to the
 firmware unchanged; they just don't have host-side timeouts so they
 remain silent regardless of firmware acknowledgment. Power
 consumption goes up if the firmware actually CAN do PSM (we'd be
 keeping the chip awake unnecessarily), but on a chip where the
 counter trips this trade-off is forced anyway: the chip stayed awake
 under the broken cascade as well, just with constant SDIO churn.
 Net effect on dmesg: after ~15s of boot, the three-line cascade stops
 firing entirely. The firmware-side wedge is observed once per boot
 (captured by the pm_unsupported latch) instead of per-cycle.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/bes_pwr.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++-
 bes2600/bes_pwr.h |  9 ++++++
 2 files changed, 78 insertions(+), 1 deletion(-)
 diff --git a/drivers/staging/bes2600/bes_pwr.c b/drivers/staging/bes2600/bes_pwr.c
 index 5798e8a..ec91485 100644
 --- a/drivers/staging/bes2600/bes_pwr.c
 +++ b/drivers/staging/bes2600/bes_pwr.c
@@ -467,6 +467,45 @@ static void bes2600_pwr_device_enter_lp_mode(struct bes2600_common *hw_priv)
 	bes_devel("device enter sleep\n");
 }
 +/*
 + * Number of consecutive bes2600_pwr_enter_lp_mode timeouts (with zero
 + * PM_INDICATIONs received) before we conclude the firmware does not
 + * honor host-driven PSM and switch to a sticky skip path.
 + */
 +#define BES2600_PM_UNSUPPORTED_THRESHOLD	3
 +
 +/*
 + * Latch pm_unsupported = true and force chip_pm_state = ACTIVE so the
 + * c6.2 wake-side skip branch covers bes2600_pwr_device_exit_lp_mode.
 + * Called after BES2600_PM_UNSUPPORTED_THRESHOLD consecutive enter_lp_mode
 + * timeouts with zero PM_INDICATIONs.
 + */
 +static void bes2600_pwr_latch_pm_unsupported(struct bes2600_common *hw_priv)
 +{
 +	bes_warn("PSM not honored (%u timeouts), switching to skip mode\n",
 +		 hw_priv->bes_power.pm_consecutive_timeouts);
 +	hw_priv->bes_power.pm_unsupported = true;
 +	atomic_set(&hw_priv->bes_power.chip_pm_state,
 +		   BES2600_CHIP_PM_ACTIVE);
 +
 +	/*
 +	 * Hold the MCU wake-flag bit permanently. Without this, every
 +	 * sdio_rx_work invocation hits bes2600_gpio_wakeup_mcu(SDIO_RX)
 +	 * when gpio_wakup_flags == 0, drives the GPIO high and msleeps
 +	 * 10 ms per RX. With ~50 RX/s of beacons + multicast that's
 +	 * ~50%% of the bes_sdio workqueue thread blocked in msleep,
 +	 * which directly caps RX throughput. Holding the MCU bit makes
 +	 * those calls bit-only bookkeeping (gpio_wakeup = (flags == 0)
 +	 * stays false, no GPIO toggle, no msleep). The bit is never
 +	 * cleared once pm_unsupported is set because
 +	 * bes2600_pwr_device_enter_lp_mode is unreachable under the
 +	 * early-return.
 +	 */
 +	if (hw_priv->sbus_ops->gpio_wake)
 +		hw_priv->sbus_ops->gpio_wake(hw_priv->sbus_priv,
 +					     GPIO_WAKE_FLAG_MCU);
 +}
 +
 static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 {
 	int i = 0;
@@ -476,6 +515,17 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 	char ip_str[20];
 	unsigned long status = 0;
 +	/*
 +	 * Sticky early-return when we've previously concluded the firmware
 +	 * doesn't honor PSM. Each attempt would otherwise burn 5s on a
 +	 * doomed wait_for_completion_timeout and produce a noisy three-line
 +	 * cascade in dmesg every time power_down_work retries (every
 +	 * ~10s). The chip stays in active mode, which on this firmware is
 +	 * the de-facto state anyway.
 +	 */
 +	if (hw_priv->bes_power.pm_unsupported)
 +		return -EOPNOTSUPP;
 +
 	/* set interface low power configuration */
 	bes2600_for_each_vif(hw_priv, priv, i) {
 #ifdef P2P_MULTIVIF
@@ -569,6 +619,9 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 						atomic_set(&hw_priv->bes_power.chip_pm_state,
 							   BES2600_CHIP_PM_UNKNOWN);
 						timeouts++;
 +						if (++hw_priv->bes_power.pm_consecutive_timeouts
 +						    >= BES2600_PM_UNSUPPORTED_THRESHOLD)
 +							bes2600_pwr_latch_pm_unsupported(hw_priv);
 					}
 				}
 			} else {
@@ -607,7 +660,8 @@ static int bes2600_pwr_enter_lp_mode(struct bes2600_common *hw_priv)
 		 * GPIO stays high and the bit clear here is purely
 		 * bookkeeping (so the next gpio_wake doesn't no-op).
 		 */
 -		if (hw_priv->sbus_ops->gpio_sleep)
 +		if (!hw_priv->bes_power.pm_unsupported &&
 +		    hw_priv->sbus_ops->gpio_sleep)
 			hw_priv->sbus_ops->gpio_sleep(hw_priv->sbus_priv,
 						      GPIO_WAKE_FLAG_MCU);
 		ret = -ETIMEDOUT;
@@ -930,6 +984,8 @@ void bes2600_pwr_init(struct bes2600_common *hw_priv)
         mutex_init(&hw_priv->bes_power.pwr_mutex);
         atomic_set(&hw_priv->bes_power.dev_state, 0);
 	atomic_set(&hw_priv->bes_power.chip_pm_state, BES2600_CHIP_PM_UNKNOWN);
 +	hw_priv->bes_power.pm_unsupported = false;
 +	hw_priv->bes_power.pm_consecutive_timeouts = 0;
         init_completion(&hw_priv->bes_power.pm_enter_cmpl);
         sema_init(&hw_priv->bes_power.sync_lock, 1);
         device_set_wakeup_capable(hw_priv->pdev, true);
@@ -1319,6 +1375,18 @@ void bes2600_pwr_notify_ps_changed(struct bes2600_common *hw_priv, u8 psmode)
 	 * indication can prime a future wait against a freshly
 	 * reinit_completion()'ed state.
 	 */
 +	/*
 +	 * Any PM indication, whatever its psmode, proves the firmware is
 +	 * actually emitting them. Reset the consecutive-timeout counter
 +	 * so a transient stall doesn't permanently disable PSM, and clear
 +	 * pm_unsupported if a previous run had latched it.
 +	 */
 +	hw_priv->bes_power.pm_consecutive_timeouts = 0;
 +	if (hw_priv->bes_power.pm_unsupported) {
 +		bes_warn("PM indication arrived after pm_unsupported was set; re-enabling PSM transitions\n");
 +		hw_priv->bes_power.pm_unsupported = false;
 +	}
 +
 	if ((psmode & 0x01) != WSM_PSM_ACTIVE) {
 		atomic_set(&hw_priv->bes_power.chip_pm_state,
 			   BES2600_CHIP_PM_LP);
 diff --git a/drivers/staging/bes2600/bes_pwr.h b/drivers/staging/bes2600/bes_pwr.h
 index 6bc44ac..92de90b 100644
 --- a/drivers/staging/bes2600/bes_pwr.h
 +++ b/drivers/staging/bes2600/bes_pwr.h
@@ -121,6 +121,15 @@ struct bes2600_pwr_t
         struct bes2600_pwr_event_t pwr_events[BES2600_DELAY_EVENT_NUM];
         atomic_t pm_set_in_process;
 	atomic_t chip_pm_state;
 +	/*
 +	 * Sticky flag set after BES2600_PM_UNSUPPORTED_THRESHOLD
 +	 * consecutive enter_lp_mode timeouts with zero PM_INDICATIONs
 +	 * received from firmware. Indicates this chip's firmware does
 +	 * not honor host-driven PSM transitions; further attempts are
 +	 * skipped to avoid the 5s timeout cascade.
 +	 */
 +	bool pm_unsupported;
 +	unsigned int pm_consecutive_timeouts;
 };
 #ifdef CONFIG_BES2600_WOWLAN
 -- 
 2.54.0
@@ -0,0 +1,83 @@
 From d48f2ae73ca17761d7a64aa645b4629641c8be5d Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Tue, 28 Apr 2026 21:37:37 +0200
 Subject: [PATCH 07/20] bes2600: handle multi-function SDIO cards in
 mmc_hw_reset bus_reset
 c5.2 (recover-wedged-firmware-via-mmc-hw-reset) wraps mmc_hw_reset()
 and treats any non-zero return as a recovery failure. On
 single-function SDIO cards mmc_hw_reset returns 0 after doing the
 remove + rescan inline. On multi-function cards (BES2600 has WLAN
 func 1 + BT companion func 2) the kernel's mmc_sdio_hw_reset() does
 NOT do the rescan: it tears the card down and returns 1 to signal
 "caller must trigger rescan".
 Field observation on PineTab2 (linux-pinetab2 6.19.10-danctnix1):
 when a real LMAC wedge fired bes2600_chrdev_wifi_force_close ->
 bes2600_chrdev_do_bus_reset, mmc_hw_reset returned 1, c5.2's wrapper
 treated that as "bus_reset failed: 1", logged the error, and gave
 up. The card was already removed (mmc2: card 0001 removed) but
 nothing scheduled a rescan; wifi (and the BT companion which shares
 the same SDIO host) stayed silent until the user rebooted four
 minutes later.
 Fix:
  - Capture the mmc_host pointer before calling mmc_hw_reset (the
    card pointer is invalid after the remove).
  - On positive return (multi-function path), log informationally
    and call mmc_detect_change(host, 0) to schedule a rescan.
    Return 0 so callers see the recovery as successful.
  - Negative return is still treated as failure as before.
 The mmc_detect_change side effect is asynchronous; the chrdev's
 wait_event_timeout(probe_done_wq, !sbus_priv) still observes the
 remove half synchronously, and the rescan + re-probe runs out of
 the host detect work afterwards.
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/bes2600_sdio.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)
 diff --git a/drivers/staging/bes2600/bes2600_sdio.c b/drivers/staging/bes2600/bes2600_sdio.c
 index deefba9..c0b67b0 100644
 --- a/drivers/staging/bes2600/bes2600_sdio.c
 +++ b/drivers/staging/bes2600/bes2600_sdio.c
@@ -1789,10 +1789,32 @@ static void bes2600_sdio_halt_device(struct sbus_priv *self)
  */
 static int bes2600_sdio_bus_reset(struct sbus_priv *self)
 {
 +	struct mmc_host *host;
 +	int ret;
 +
 	if (!self || !self->func || !self->func->card)
 		return -EINVAL;
 -	return mmc_hw_reset(self->func->card);
 +	host = self->func->card->host;
 +	ret = mmc_hw_reset(self->func->card);
 +
 +	/*
 +	 * On multi-function SDIO cards (BES2600 has WLAN func 1 + BT
 +	 * companion func 2), mmc_sdio_hw_reset() removes the card and
 +	 * returns 1 to signal "remove happened, caller must trigger
 +	 * rescan". The kernel does NOT auto-rescan in this case;
 +	 * single-function cards take the rescan path inline and return 0.
 +	 * Treat any non-negative return as success and force a rescan if
 +	 * mmc_hw_reset signalled the multi-function path - otherwise the
 +	 * card stays removed indefinitely after a wedge recovery,
 +	 * leaving wifi (and the BT companion) silent until reboot.
 +	 */
 +	if (ret > 0) {
 +		bes_info("multi-func mmc_hw_reset removed card; scheduling rescan\n");
 +		mmc_detect_change(host, 0);
 +		ret = 0;
 +	}
 +	return ret;
 }
 static bool bes2600_sdio_wakeup_source(struct sbus_priv *self)
 -- 
 2.54.0
@@ -0,0 +1,221 @@
 From 3b4239ad2b7976eab04ccae748e36fb78422874f Mon Sep 17 00:00:00 2001
 From: "Claude (noether)" <claude@reauktion.de>
 Date: Wed, 6 May 2026 19:50:52 +0200
 Subject: [PATCH 08/20] bes2600: pre-empt AP-deauth-6 with mac80211 reassoc on
 decrypt-fail storm
 When the BES2600 firmware reports WSM_STATUS_DECRYPTFAILURE for a burst
 of received frames (typically because the host's PTK or GTK has fallen
 out of sync with the AP), the AP eventually concludes that the STA is
 not authenticated and emits an unprotected deauth-reason-6 ("Class 2
 frame received from non-authenticated station"). On the deployed
 pinetab2 + bes2600 stack this AP-initiated deauth has been observed to
 leave the link blackholed for up to 109 s before userspace finds a
 different SSID/channel to recover on. (Receipts at
 https://git.reauktion.de/marfrit/besser, notes/phase5-2026-05-06.md.)
 Add a sliding-window counter on each bes2600_vif: when 5 decrypt
 failures fire within 5 s, schedule a worker that calls
 ieee80211_connection_loss(vif). mac80211 then performs immediate
 disassociation; userspace (NetworkManager / wpa_supplicant) reconnects
 with fresh keys before the AP gets a chance to fire its unprotected
 deauth.
 Predicted Phase 7 delta vs the unpatched baseline:
 - decrypt-burst rate: unchanged (this does not address root cause)
 - AP-deauth-6 rate: <= 0.2 of baseline
 - conditional probability of >5s blackhole given a burst:
  100% -> <= 10%
 - worst-case recovery time: 109s -> <5s
 Contract pin: ieee80211_connection_loss() per
 include/net/mac80211.h: "may also be called if the connection needs to
 be terminated for some other reason... will cause immediate change to
 disassociated state, without connection recovery attempts." Userspace
 recovery is the existing NM/wpa_supplicant path. The worker context
 satisfies the implicit process-context expectation.
 Files touched:
 - bes2600/bes2600.h: 4 new fields on struct bes2600_vif + 2 prototypes
 - bes2600/txrx.c: new helpers + the call site at the existing
  WSM_STATUS_DECRYPTFAILURE log point (the unconditional "goto drop"
  branch in bes2600_rx_cb)
 - bes2600/sta.c: bes2600_decrypt_storm_init() in bes2600_vif_setup;
  cancel_work_sync() in bes2600_remove_interface, alongside the
  existing per-vif cancel_*_work_sync block. Safe under the kernel
  cancel_work_sync contract: the work_struct is INIT_WORK'd in setup,
  so the call is valid; it blocks until any in-flight handler returns,
  ensuring no use-after-free of priv when mac80211 frees the vif; and
  it is idempotent (subsequent calls just return false).
 - bes2600/debug.c: DecryptStormRecoveries seq_printf in the per-vif
  status seq_file output
 Threshold (5/5s) is set well above the steady-state per-vif decrypt-
 fail rate observed in measurement (~1/min even under sustained 1 MB/s
 load), so a true storm is required to trip it. The cw1200/cw1260
 ancestor has no equivalent storm-recovery; this is a clean addition.
 checkpatch.pl --no-tree --strict: clean (0/0/0).
 Signed-off-by: Claude (noether) <claude@reauktion.de>
 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
 ---
 bes2600/bes2600.h |  9 ++++++
 bes2600/debug.c   |  2 ++
 bes2600/sta.c     |  2 ++
 bes2600/txrx.c    | 74 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 87 insertions(+)
 diff --git a/drivers/staging/bes2600/bes2600.h b/drivers/staging/bes2600/bes2600.h
 index 0e60960..66482f7 100644
 --- a/drivers/staging/bes2600/bes2600.h
 +++ b/drivers/staging/bes2600/bes2600.h
@@ -596,6 +596,11 @@ struct bes2600_vif {
         unsigned long           rx_timestamp;
         u32                     cipherType;
 +	/* Decrypt-storm fast-recover (Trigger B). See txrx.c. */
 +	unsigned long			decrypt_storm_window_start;
 +	unsigned int			decrypt_storm_count;
 +	unsigned int			decrypt_storm_recoveries;
 +	struct work_struct		decrypt_storm_recover_work;
 	/* AP powersave */
 	u32			link_id_map;
@@ -856,4 +861,8 @@ int bes2600_btusb_setup_pipes(struct sbus_priv *sbus_priv);
 void bes2600_btusb_uninit(struct usb_interface *interface);
 #endif
 +/* Decrypt-storm fast-recover helpers — see txrx.c. */
 +void bes2600_decrypt_storm_init(struct bes2600_vif *priv);
 +void bes2600_decrypt_storm_account(struct bes2600_vif *priv);
 +
 #endif /* BES2600_H */
 diff --git a/drivers/staging/bes2600/debug.c b/drivers/staging/bes2600/debug.c
 index 5228b22..ca223dd 100644
 --- a/drivers/staging/bes2600/debug.c
 +++ b/drivers/staging/bes2600/debug.c
@@ -542,6 +542,8 @@ static int bes2600_status_show_priv(struct seq_file *seq, void *v)
 		priv->listening ? " (listening)" : "");
 	seq_printf(seq, "Assoc:      %s\n",
 		bes2600_debug_join_status[priv->join_status]);
 +	seq_printf(seq, "DecryptStormRecoveries: %u\n",
 +		   priv->decrypt_storm_recoveries);
 	if (priv->rx_filter.promiscuous)
 		seq_puts(seq,   "Filter:     promisc\n");
 	else if (priv->rx_filter.fcs)
 diff --git a/drivers/staging/bes2600/sta.c b/drivers/staging/bes2600/sta.c
 index ca1c77c..ee9fd81 100644
 --- a/drivers/staging/bes2600/sta.c
 +++ b/drivers/staging/bes2600/sta.c
@@ -464,6 +464,7 @@ void bes2600_remove_interface(struct ieee80211_hw *dev,
 	cancel_delayed_work_sync(&priv->join_timeout);
 	cancel_delayed_work_sync(&priv->set_cts_work);
 	cancel_delayed_work_sync(&priv->pending_offchanneltx_work);
 +	cancel_work_sync(&priv->decrypt_storm_recover_work);
 	timer_delete_sync(&priv->mcast_timeout);
 	/* TODO:COMBO: May be reset of these variables "delayed_link_loss and
@@ -2639,6 +2640,7 @@ int bes2600_vif_setup(struct bes2600_vif *priv)
 	/* Setup per vif workitems and locks */
 	spin_lock_init(&priv->vif_lock);
 +	bes2600_decrypt_storm_init(priv);
 	INIT_WORK(&priv->join_work, bes2600_join_work);
 	INIT_DELAYED_WORK(&priv->join_timeout, bes2600_join_timeout);
 	INIT_WORK(&priv->unjoin_work, bes2600_unjoin_work);
 diff --git a/drivers/staging/bes2600/txrx.c b/drivers/staging/bes2600/txrx.c
 index 017f0d8..f6a66d6 100644
 --- a/drivers/staging/bes2600/txrx.c
 +++ b/drivers/staging/bes2600/txrx.c
@@ -26,6 +26,78 @@
 #define BES2600_INVALID_RATE_ID (0xFF)
 +/*
 + * Decrypt-storm fast-recover (Trigger B).
 + *
 + * When the BES2600 firmware reports WSM_STATUS_DECRYPTFAILURE for a
 + * burst of received frames (typically because the host's PTK or GTK
 + * has fallen out of sync with the AP), the AP eventually concludes that
 + * the STA is not authenticated and emits an unprotected deauth-reason-6
 + * ("Class 2 frame received from non-authenticated station"). On the
 + * deployed pinetab2 + bes2600 stack this AP-initiated deauth has been
 + * observed to leave the link blackholed for up to 109 s before
 + * userspace finds a different SSID/channel to recover on. (Receipts at
 + * https://git.reauktion.de/marfrit/besser, notes/phase5-2026-05-06.md.)
 + *
 + * Recovery here pre-empts the AP: when we see THRESHOLD decrypt
 + * failures within WINDOW, we ask mac80211 for a clean reassoc via
 + * ieee80211_connection_loss(), which causes immediate disassociation
 + * and lets userspace auto-reconnect with fresh keys.
 + *
 + * mac80211 contract: ieee80211_connection_loss() may be called
 + * regardless of IEEE80211_HW_CONNECTION_MONITOR; it causes immediate
 + * disassociation without driver-side recovery attempts. See
 + * include/net/mac80211.h for the canonical doc-comment.
 + *
 + * The threshold is set well above the steady-state per-vif
 + * decrypt-fail rate observed in measurement (~1/min even under
 + * sustained 1 MB/s load), so a true storm is required to trip it.
 + */
 +#define BES2600_DECRYPT_STORM_THRESHOLD	5
 +#define BES2600_DECRYPT_STORM_WINDOW_MS	5000
 +
 +static void bes2600_decrypt_storm_recover_work(struct work_struct *work)
 +{
 +	struct bes2600_vif *priv = container_of(work, struct bes2600_vif,
 +						decrypt_storm_recover_work);
 +
 +	if (!priv->vif)
 +		return;
 +
 +	bes_warn("[bes2600] decrypt-storm fast-recover: forcing reassoc\n");
 +	ieee80211_connection_loss(priv->vif);
 +	priv->decrypt_storm_recoveries++;
 +}
 +
 +void bes2600_decrypt_storm_init(struct bes2600_vif *priv)
 +{
 +	INIT_WORK(&priv->decrypt_storm_recover_work,
 +		  bes2600_decrypt_storm_recover_work);
 +	priv->decrypt_storm_window_start = 0;
 +	priv->decrypt_storm_count = 0;
 +	priv->decrypt_storm_recoveries = 0;
 +}
 +
 +void bes2600_decrypt_storm_account(struct bes2600_vif *priv)
 +{
 +	unsigned long now = jiffies;
 +	unsigned long window = msecs_to_jiffies(BES2600_DECRYPT_STORM_WINDOW_MS);
 +
 +	if (priv->decrypt_storm_window_start == 0 ||
 +	    time_after(now, priv->decrypt_storm_window_start + window)) {
 +		priv->decrypt_storm_window_start = now;
 +		priv->decrypt_storm_count = 1;
 +		return;
 +	}
 +
 +	if (++priv->decrypt_storm_count >= BES2600_DECRYPT_STORM_THRESHOLD) {
 +		priv->decrypt_storm_count = 0;
 +		/* Skew the window so we don't re-fire on the same storm. */
 +		priv->decrypt_storm_window_start = now + window;
 +		schedule_work(&priv->decrypt_storm_recover_work);
 +	}
 +}
 +
 #ifdef CONFIG_BES2600_TESTMODE
 #include "bes_nl80211_testmode_msg.h"
 #endif /* CONFIG_BES2600_TESTMODE */
@@ -1694,6 +1766,8 @@ void bes2600_rx_cb(struct bes2600_vif *priv,
 			goto drop;
 		} else {
 			bes_warn("[RX] Receive failure: %d.\n", arg->status);
 +			if (arg->status == WSM_STATUS_DECRYPTFAILURE)
 +				bes2600_decrypt_storm_account(priv);
 			goto drop;
 		}
 	}
 -- 
 2.54.0
@@ -0,0 +1,279 @@
 From a7e232738d50c797bb2be1e71cbe1578a1d46dda Mon Sep 17 00:00:00 2001
 From: "Claude (noether)" <claude@reauktion.de>
 Date: Thu, 7 May 2026 11:30:09 +0200
 Subject: [PATCH 09/20] bes2600: bus_reset on connection-loss storm to dodge
 assoc-comeback blackhole
 When mac80211 declares connection loss against this AP (typically driven
 by inactivity-deauth or beacon-loss), the userspace reauth that follows
 sometimes enters a long blackhole: the AP responds to auth with success
 but defers assoc with the 802.11v "assoc comeback" timer; ohm retries
 faster than the comeback grants permission; the AP eventually fires an
 unprotected deauth-reason-6 ("Class 2 frame received from non-
 authenticated station"), and recovery only completes via cross-SSID or
 cross-channel fallback. Receipts: ~86 s blackhole observed in the
 phase-7 rep on 2026-05-07 02:42, with three subsequent BSSIDs returning
 assoc comeback timeouts before reason-9 (STA_REQ_ASSOC_WITHOUT_AUTH)
 fired. Documented in marfrit/besser:notes/phase4-2026-05-07.md.
 When N=3 driver-side connection_loss decisions fire within a 60 s window
 on the same vif, skip the ieee80211_connection_loss() path and trigger
 the c5.2-introduced bes2600_chrdev_do_bus_reset() instead. The bus
 reset removes and re-probes the chip; userspace re-associates with a
 fresh chip state, dodging the AP's comeback-timer rejection cycle.
 Predicted Phase 7 delta vs current baseline:
 - api_connection_loss rate: unchanged (we don't address the trigger)
 - conditional probability of >5 s blackhole given event: <= 30 %
 - worst-case recovery: 86 s -> < 10 s
 Contract pin: bes2600_chrdev_do_bus_reset(sbus_ops, sbus_priv) at
 bes2600/bes_chardev.c:455, introduced by c5.2. The function is async-
 returning: sbus_ops->bus_reset() schedules an SDIO rescan; the helper
 waits up to 3 s for the remove() callback to clear sbus_priv, then
 returns. Per-vif state is gone after this point, so the recover work
 lives on bes2600_common (hw_priv) and uses the global bes2600_cdev for
 the bus_reset call rather than dereferencing per-vif state.
 Threshold (3 / 60 s) is well above the steady-state per-vif
 connection_loss rate observed in the patch-A phase-7 rep (0.86/h under
 sustained load), so a true storm is required to trip it.
 Files touched:
 - bes2600/bes2600.h: 3 counter fields on struct bes2600_vif, 1
  work_struct on struct bes2600_common, 3 prototypes
 - bes2600/sta.c: 3 helpers + storm-account hook in
  bes2600_connection_loss_work + storm-init in bes2600_vif_setup +
  cancel_work_sync in the hw_priv shutdown path; #include bes_chardev.h
  was already pulled in by an earlier c-stack patch
 - bes2600/main.c: INIT_WORK alongside other hw_priv work_structs
 - bes2600/debug.c: ConnectionLossStormRecoveries seq_printf in the
  per-vif status seq_file output
 The cw1200/cw1260 ancestor has no equivalent; this is a clean
 addition. checkpatch.pl --no-tree --strict: clean (0/0/0).
 Signed-off-by: Claude (noether) <claude@reauktion.de>
 ---
 bes2600/bes2600.h     | 12 +++++++
 bes2600/bes_chardev.c | 12 +++++++
 bes2600/bes_chardev.h |  1 +
 bes2600/debug.c       |  2 ++
 bes2600/main.c        |  2 ++
 bes2600/sta.c         | 82 +++++++++++++++++++++++++++++++++++++++++--
 6 files changed, 109 insertions(+), 2 deletions(-)
 diff --git a/drivers/staging/bes2600/bes2600.h b/drivers/staging/bes2600/bes2600.h
 index 66482f7..ec41141 100644
 --- a/drivers/staging/bes2600/bes2600.h
 +++ b/drivers/staging/bes2600/bes2600.h
@@ -511,6 +511,9 @@ struct bes2600_common {
 	struct list_head coex_event_list;
 	spinlock_t coex_event_lock;
 +	/* Connection-loss-storm fast-recover (Trigger A). See sta.c. */
 +	struct work_struct connection_loss_storm_recover_work;
 +
 	/* member for low power */
 	struct bes2600_pwr_t bes_power;
@@ -627,6 +630,10 @@ struct bes2600_vif {
 	/* CQM Implementation */
 	struct delayed_work	bss_loss_work;
 	struct delayed_work	connection_loss_work;
 +	/* Connection-loss-storm fast-recover (Trigger A). See sta.c. */
 +	unsigned long		connection_loss_storm_window_start;
 +	unsigned int		connection_loss_storm_count;
 +	unsigned int		connection_loss_storm_recoveries;
 	struct work_struct	tx_failure_work;
 	int			delayed_link_loss;
 	spinlock_t		bss_loss_lock;
@@ -865,4 +872,9 @@ void bes2600_btusb_uninit(struct usb_interface *interface);
 void bes2600_decrypt_storm_init(struct bes2600_vif *priv);
 void bes2600_decrypt_storm_account(struct bes2600_vif *priv);
 +/* Connection-loss-storm fast-recover helpers — see sta.c. */
 +void bes2600_connection_loss_storm_init(struct bes2600_vif *priv);
 +bool bes2600_connection_loss_storm_account(struct bes2600_vif *priv);
 +void bes2600_connection_loss_storm_recover(struct work_struct *work);
 +
 #endif /* BES2600_H */
 diff --git a/drivers/staging/bes2600/bes_chardev.c b/drivers/staging/bes2600/bes_chardev.c
 index a74bf60..df6b911 100644
 --- a/drivers/staging/bes2600/bes_chardev.c
 +++ b/drivers/staging/bes2600/bes_chardev.c
@@ -1120,6 +1120,18 @@ int bes2600_chrdev_do_bus_reset(const struct sbus_ops *sbus_ops, struct sbus_pri
 	return 0;
 }
 +/*
 + * Trigger bes2600_chrdev_do_bus_reset() against the file-global
 + * bes2600_cdev. Used by host-side recovery paths outside this
 + * compilation unit (e.g. sta.c connection-loss-storm fast-recover) so
 + * those callers do not need to reach the static bes2600_cdev directly.
 + */
 +int bes2600_chrdev_trigger_bus_reset(void)
 +{
 +	return bes2600_chrdev_do_bus_reset(bes2600_cdev.sbus_ops,
 +					   bes2600_cdev.sbus_priv);
 +}
 +
 bool bes2600_chrdev_is_wifi_opened(void)
 {
 	bool wifi_opened = false;
 diff --git a/drivers/staging/bes2600/bes_chardev.h b/drivers/staging/bes2600/bes_chardev.h
 index ca8419e..2a7cad7 100644
 --- a/drivers/staging/bes2600/bes_chardev.h
 +++ b/drivers/staging/bes2600/bes_chardev.h
@@ -61,6 +61,7 @@ struct sbus_priv *bes2600_chrdev_get_sbus_priv_data(void);
 int bes2600_chrdev_check_system_close(void);
 int bes2600_chrdev_do_system_close(const struct sbus_ops *sbus_ops, struct sbus_priv *priv);
 int bes2600_chrdev_do_bus_reset(const struct sbus_ops *sbus_ops, struct sbus_priv *priv);
 +int bes2600_chrdev_trigger_bus_reset(void);
 void bes2600_chrdev_wakeup_bt(void);
 void bes2600_chrdev_wifi_force_close(struct bes2600_common *hw_priv, bool halt_dev);
 void bes2600_chrdev_usb_remove(struct bes2600_common *hw_priv);
 diff --git a/drivers/staging/bes2600/debug.c b/drivers/staging/bes2600/debug.c
 index ca223dd..0d68392 100644
 --- a/drivers/staging/bes2600/debug.c
 +++ b/drivers/staging/bes2600/debug.c
@@ -544,6 +544,8 @@ static int bes2600_status_show_priv(struct seq_file *seq, void *v)
 		bes2600_debug_join_status[priv->join_status]);
 	seq_printf(seq, "DecryptStormRecoveries: %u\n",
 		   priv->decrypt_storm_recoveries);
 +	seq_printf(seq, "ConnectionLossStormRecoveries: %u\n",
 +		   priv->connection_loss_storm_recoveries);
 	if (priv->rx_filter.promiscuous)
 		seq_puts(seq,   "Filter:     promisc\n");
 	else if (priv->rx_filter.fcs)
 diff --git a/drivers/staging/bes2600/main.c b/drivers/staging/bes2600/main.c
 index 3b0b7a3..000329c 100644
 --- a/drivers/staging/bes2600/main.c
 +++ b/drivers/staging/bes2600/main.c
@@ -489,6 +489,8 @@ static struct ieee80211_hw *bes2600_init_common(size_t hw_priv_data_len)
 	spin_lock_init(&hw_priv->rtsvalue_lock);
 	INIT_WORK(&hw_priv->dynamic_opt_txrx_work, bes2600_dynamic_opt_txrx_work);
 	INIT_WORK(&hw_priv->tx_policy_upload_work, tx_policy_upload_work);
 +	INIT_WORK(&hw_priv->connection_loss_storm_recover_work,
 +		  bes2600_connection_loss_storm_recover);
 	spin_lock_init(&hw_priv->event_queue_lock);
 	INIT_LIST_HEAD(&hw_priv->event_queue);
 	INIT_WORK(&hw_priv->event_handler, bes2600_event_handler);
 diff --git a/drivers/staging/bes2600/sta.c b/drivers/staging/bes2600/sta.c
 index ee9fd81..ec67d38 100644
 --- a/drivers/staging/bes2600/sta.c
 +++ b/drivers/staging/bes2600/sta.c
@@ -268,6 +268,7 @@ void bes2600_stop(struct ieee80211_hw *dev, bool suspend)
 	cancel_work_sync(&hw_priv->coex_work);
 	coex_stop(hw_priv);
 #endif
 +	cancel_work_sync(&hw_priv->connection_loss_storm_recover_work);
 	bes2600_wifi_stop(hw_priv);
@@ -1675,6 +1676,70 @@ report:
 	spin_unlock(&priv->bss_loss_lock);
 }
 +/*
 + * Connection-loss-storm fast-recover (Trigger A).
 + *
 + * bes2600_connection_loss_work below is the driver's own decision-point
 + * to give up on a BSS (after bss-loss detection accumulates beyond
 + * tolerance) and tell mac80211 via ieee80211_connection_loss(). On the
 + * deployed pinetab2 stack a single ieee80211_connection_loss() event
 + * sometimes triggers a userspace reauth blackhole (assoc-comeback
 + * timeouts followed by AP unprotected-deauth-reason-6) that ends only
 + * via cross-channel/cross-SSID fallback and can take 80+ s. Receipts at
 + * https://git.reauktion.de/marfrit/besser, notes/phase4-2026-05-07.md.
 + *
 + * When N connection-loss decisions land within WINDOW on the same vif,
 + * skip the ieee80211_connection_loss() path and trigger a chip-level
 + * bus_reset (the c5.2-introduced bes2600_chrdev_do_bus_reset). The chip
 + * is removed and re-probed; userspace re-associates from a fresh state,
 + * dodging the assoc-comeback loop.
 + *
 + * Threshold (3 / 60 s) is chosen well above the steady-state per-vif
 + * connection-loss rate observed in the patch-A Phase-7 rep
 + * (0.86/h under sustained load), so a true storm is required.
 + *
 + * The recover work_struct lives on bes2600_common (hw_priv) so that
 + * scheduling it does not race with vif teardown after bus_reset frees
 + * the per-vif state.
 + */
 +#define BES2600_CONNECTION_LOSS_STORM_THRESHOLD	3
 +#define BES2600_CONNECTION_LOSS_STORM_WINDOW_MS	60000
 +
 +void bes2600_connection_loss_storm_recover(struct work_struct *work)
 +{
 +	bes_warn("[bes2600] connection-loss-storm fast-recover: bus_reset\n");
 +	bes2600_chrdev_trigger_bus_reset();
 +	/*
 +	 * After bes2600_chrdev_do_bus_reset() returns, the SDIO core has
 +	 * scheduled a remove + rescan; per-vif state may already be gone.
 +	 * Do not dereference any per-vif pointer here.
 +	 */
 +}
 +
 +void bes2600_connection_loss_storm_init(struct bes2600_vif *priv)
 +{
 +	priv->connection_loss_storm_window_start = 0;
 +	priv->connection_loss_storm_count = 0;
 +	priv->connection_loss_storm_recoveries = 0;
 +}
 +
 +bool bes2600_connection_loss_storm_account(struct bes2600_vif *priv)
 +{
 +	unsigned long now = jiffies;
 +	unsigned long window =
 +		msecs_to_jiffies(BES2600_CONNECTION_LOSS_STORM_WINDOW_MS);
 +
 +	if (priv->connection_loss_storm_window_start == 0 ||
 +	    time_after(now, priv->connection_loss_storm_window_start + window)) {
 +		priv->connection_loss_storm_window_start = now;
 +		priv->connection_loss_storm_count = 1;
 +		return false;
 +	}
 +
 +	return ++priv->connection_loss_storm_count >=
 +	       BES2600_CONNECTION_LOSS_STORM_THRESHOLD;
 +}
 +
 void bes2600_connection_loss_work(struct work_struct *work)
 {
 	struct bes2600_vif *priv =
@@ -1684,9 +1749,21 @@ void bes2600_connection_loss_work(struct work_struct *work)
 	bes_devel("[CQM] Reporting connection loss.\n");
 	bes2600_pwr_clear_busy_event(priv->hw_priv, BES_PWR_LOCK_ON_BSS_LOST);
 -	if(bes2600_suspend_status_get(hw_priv)) {
 +
 +	if (bes2600_connection_loss_storm_account(priv)) {
 +		bes_warn("[bes2600] connection-loss storm: %u in %u s, scheduling bus reset\n",
 +			 priv->connection_loss_storm_count,
 +			 BES2600_CONNECTION_LOSS_STORM_WINDOW_MS / 1000);
 +		priv->connection_loss_storm_count = 0;
 +		priv->connection_loss_storm_recoveries++;
 +		schedule_work(&hw_priv->connection_loss_storm_recover_work);
 +		/* bus_reset will tear the chip down; skip the mac80211 path. */
 +		return;
 +	}
 +
 +	if (bes2600_suspend_status_get(hw_priv))
 		bes2600_pending_unjoin_set(hw_priv, priv->if_id);
 -	} else
 +	else
 		ieee80211_connection_loss(priv->vif);
 #ifdef WIFI_BT_COEXIST_EPTA_ENABLE
 	// set disconnected in BSS_CHANGED_ASSOC
@@ -2641,6 +2718,7 @@ int bes2600_vif_setup(struct bes2600_vif *priv)
 	/* Setup per vif workitems and locks */
 	spin_lock_init(&priv->vif_lock);
 	bes2600_decrypt_storm_init(priv);
 +	bes2600_connection_loss_storm_init(priv);
 	INIT_WORK(&priv->join_work, bes2600_join_work);
 	INIT_DELAYED_WORK(&priv->join_timeout, bes2600_join_timeout);
 	INIT_WORK(&priv->unjoin_work, bes2600_unjoin_work);
 -- 
 2.54.0
@@ -0,0 +1,92 @@
 From d9268b433abc035c6e3f63a26191df5855b09b61 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Thu, 7 May 2026 21:19:49 +0200
 Subject: [PATCH 10/20] bes2600: replace a set of atomic_add()
 Backport of cw1200 mainline commit 07f995ca1951 ("cw1200: replace a set
 of atomic_add()", 2020-11-10).  atomic_inc() reads more naturally than
 atomic_add(1, &x).  Mechanical change, no functional impact.
 7 sites: 6 in bh.c (bh_term, bh_rx x2, bh_tx x3) and 1 in itp.c
 (awaiting_confirm).  Two of the bh_rx and three of the bh_tx sites are
 inside the cw1200-ancestor #if 0 block; replaced anyway to keep the
 file consistent with cw1200 mainline source style.
 Cherry-picked from upstream Linux:
  07f995ca1951 cw1200: replace a set of atomic_add()
  Author: Yejune Deng <yejune.deng@gmail.com>
  Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  Link: https://lore.kernel.org/r/1604991491-27908-1-git-send-email-yejune.deng@gmail.com
 ---
 bes2600/bh.c  | 12 ++++++------
 bes2600/itp.c |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)
 diff --git a/drivers/staging/bes2600/bh.c b/drivers/staging/bes2600/bh.c
 index 175ab5e..fab3bf0 100644
 --- a/drivers/staging/bes2600/bh.c
 +++ b/drivers/staging/bes2600/bh.c
@@ -102,7 +102,7 @@ void bes2600_unregister_bh(struct bes2600_common *hw_priv)
 	coex_deinit_mode(hw_priv);
 #endif
 -	atomic_add(1, &hw_priv->bh_term);
 +	atomic_inc(&hw_priv->bh_term);
 	wake_up(&hw_priv->bh_wq);
 	flush_workqueue(hw_priv->bh_workqueue);
@@ -591,7 +591,7 @@ static int bes2600_bh(void *arg)
 			bes_devel("[BH] Device resume.\n");
 			atomic_set(&hw_priv->bh_suspend, BES2600_BH_RESUMED);
 			wake_up(&hw_priv->bh_evt_wq);
 -			atomic_add(1, &hw_priv->bh_rx);
 +			atomic_inc(&hw_priv->bh_rx);
 			continue;
 		}
@@ -759,9 +759,9 @@ tx:
 #if 0 /* count is not implemented */
 				if (ret > 1)
 -					atomic_add(1, &hw_priv->bh_tx);
 +					atomic_inc(&hw_priv->bh_tx);
 #else
 -				atomic_add(1, &hw_priv->bh_tx);
 +				atomic_inc(&hw_priv->bh_tx);
 #endif
 #if defined(CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES)
@@ -1135,7 +1135,7 @@ static int bes2600_bh_tx_helper(struct bes2600_common *hw_priv,
 	tx_len += 4;
 #endif
 -	atomic_add(1, &hw_priv->bh_tx);
 +	atomic_inc(&hw_priv->bh_tx);
 	tx_len = hw_priv->sbus_ops->align_size(
 		hw_priv->sbus_priv, tx_len);
@@ -1442,7 +1442,7 @@ static int bes2600_bh(void *arg)
 			bes_devel("[BH] Device resume.\n");
 			atomic_set(&hw_priv->bh_suspend, BES2600_BH_RESUMED);
 			wake_up(&hw_priv->bh_evt_wq);
 -			atomic_add(1, &hw_priv->bh_rx);
 +			atomic_inc(&hw_priv->bh_rx);
 			goto done;
 		}
 diff --git a/drivers/staging/bes2600/itp.c b/drivers/staging/bes2600/itp.c
 index e5c2958..c50b29c 100644
 --- a/drivers/staging/bes2600/itp.c
 +++ b/drivers/staging/bes2600/itp.c
@@ -570,7 +570,7 @@ int bes2600_itp_get_tx(struct bes2600_common *priv, u8 **data,
 	*burst = 2;
 	atomic_set(&priv->bh_tx, 1);
 	ktime_get_ts(&itp->last_sent);
 -	atomic_add(1, &itp->awaiting_confirm);
 +	atomic_inc(&itp->awaiting_confirm);
 	spin_unlock_bh(&itp->tx_lock);
 	return 1;
 -- 
 2.54.0
@@ -0,0 +1,58 @@
 From 77f966df25d24a2fb85d235bcaa6248ddc394822 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Thu, 7 May 2026 21:20:46 +0200
 Subject: [PATCH 11/20] bes2600: fix missing destroy_workqueue() on error in
 init_common
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 Two error paths between create_singlethread_workqueue() (~main.c:489)
 and the success-path destroy_workqueue() in unregister_common (~609)
 return without cleaning up the workqueue, leaking it on probe failure:
  1. bes2600_queue_stats_init() failure
  2. bes2600_queue_init() failure (any of the 4 TID queues)
 Both call ieee80211_free_hw(hw); return NULL — without first
 destroy_workqueue(hw_priv->workqueue).  Add it.
 Backport of cw1200 mainline commit 7ec8a926188e ("cw1200: fix missing
 destroy_workqueue() on error in cw1200_init_common", 2020-11-19),
 which fixed the identical bug in the same code shape we inherited.
 Reported on cw1200 by Hulk Robot.
 Cherry-picked from upstream Linux:
  7ec8a926188e cw1200: fix missing destroy_workqueue() on error
  Author: Qinglang Miao <miaoqinglang@huawei.com>
  Reported-by: Hulk Robot <hulkci@huawei.com>
  Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  Link: https://lore.kernel.org/r/20201119070842.1011-1-miaoqinglang@huawei.com
  Fixes: a910e4a94f69 ("cw1200: add driver for the ST-E CW1100 & CW1200 WLAN chipsets")
 ---
 bes2600/main.c | 2 ++
 1 file changed, 2 insertions(+)
 diff --git a/drivers/staging/bes2600/main.c b/drivers/staging/bes2600/main.c
 index 000329c..f9f5f3b 100644
 --- a/drivers/staging/bes2600/main.c
 +++ b/drivers/staging/bes2600/main.c
@@ -502,6 +502,7 @@ static struct ieee80211_hw *bes2600_init_common(size_t hw_priv_data_len)
 			WLAN_LINK_ID_MAX,
 			bes2600_skb_dtor,
 			hw_priv))) {
 +		destroy_workqueue(hw_priv->workqueue);
 		ieee80211_free_hw(hw);
 		return NULL;
 	}
@@ -513,6 +514,7 @@ static struct ieee80211_hw *bes2600_init_common(size_t hw_priv_data_len)
 			for (; i > 0; i--)
 				bes2600_queue_deinit(&hw_priv->tx_queue[i - 1]);
 			bes2600_queue_stats_deinit(&hw_priv->tx_queue_stats);
 +			destroy_workqueue(hw_priv->workqueue);
 			ieee80211_free_hw(hw);
 			return NULL;
 		}
 -- 
 2.54.0
@@ -0,0 +1,144 @@
 From 9e38ac552302b6a6bbbeeb27339b8f8ca190110f Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Thu, 7 May 2026 21:24:01 +0200
 Subject: [PATCH 12/20] bes2600: fix concurrency UAF in bes2600_hw_scan and
 sched_scan
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 bes2600_bss_info_changed() and bes2600_hw_scan() can run concurrently.
 The probe-request SKB allocated by ieee80211_probereq_get() before
 scan.lock + conf_lock are taken can be touched by a concurrent
 bss_info_changed (via wsm_set_template_frame's path) while we hold no
 lock.  Reorder to acquire both locks BEFORE the SKB allocation.
 Also reorder cleanup paths so dev_kfree_skb() runs BEFORE up() —
 otherwise a small window exists where the SKB has been touched but the
 lock has been released, allowing concurrent code to also touch it.
 Three sites fixed:
  - bes2600_hw_scan: lock-take + ENOMEM cleanup + wsm_set_template_frame
    error cleanup + success-path SKB free + lock release order
  - bes2600_sched_scan_start (#ifdef ROAM_OFFLOAD): same three sub-fixes
    (compiled-out at default build, fixed for consistency)
  - All success/error paths: dev_kfree_skb before up()
 Backport of cw1200 mainline commit 86760e0dfe36 ("cw1200: Fix
 concurrency use-after-free bugs in cw1200_hw_scan()", 2018-12-14),
 which fixed the identical bug in the same code shape we inherited.
 That commit was merged from upstream 4f68ef64cd7f.
 Cherry-picked from upstream Linux:
  86760e0dfe36 cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan()
  Author: Jia-Ju Bai <baijiaju1990@gmail.com>
  Link: https://lore.kernel.org/r/20181214035521.7575-1-baijiaju1990@gmail.com
 ---
 bes2600/scan.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)
 diff --git a/drivers/staging/bes2600/scan.c b/drivers/staging/bes2600/scan.c
 index b944adc..3cd7b64 100644
 --- a/drivers/staging/bes2600/scan.c
 +++ b/drivers/staging/bes2600/scan.c
@@ -257,18 +257,21 @@ int bes2600_hw_scan(struct ieee80211_hw *hw,
 	bes2600_pwr_set_busy_event(hw_priv, BES_PWR_LOCK_ON_SCAN);
 +	/* will be unlocked in bes2600_scan_work() */
 +	down(&hw_priv->scan.lock);
 +	down(&hw_priv->conf_lock);
 +
 	frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
 		req->ie_len);
 -	if (!frame.skb)
 +	if (!frame.skb) {
 +		up(&hw_priv->conf_lock);
 +		up(&hw_priv->scan.lock);
 		return -ENOMEM;
 +	}
 	if (req->ie_len)
 		skb_put_data(frame.skb, req->ie, req->ie_len);
 -	/* will be unlocked in bes2600_scan_work() */
 -	down(&hw_priv->scan.lock);
 -	down(&hw_priv->conf_lock);
 -
 	if (frame.skb) {
 		int ret;
 		//if (priv->if_id == 0)
@@ -286,9 +289,9 @@ int bes2600_hw_scan(struct ieee80211_hw *hw,
 		}
 #endif
 		if (ret) {
 +			dev_kfree_skb(frame.skb);
 			up(&hw_priv->conf_lock);
 			up(&hw_priv->scan.lock);
 -			dev_kfree_skb(frame.skb);
 			return ret;
 		}
 	}
@@ -318,10 +321,10 @@ int bes2600_hw_scan(struct ieee80211_hw *hw,
 		++hw_priv->scan.n_ssids;
 	}
 -	up(&hw_priv->conf_lock);
 -
 	if (frame.skb)
 		dev_kfree_skb(frame.skb);
 +
 +	up(&hw_priv->conf_lock);
 #ifdef WIFI_BT_COEXIST_EPTA_ENABLE
 	bwifi_change_current_status(hw_priv, BWIFI_STATUS_SCANNING);
 #endif
@@ -362,14 +365,18 @@ int bes2600_hw_sched_scan_start(struct ieee80211_hw *hw,
 	if (req->n_ssids > hw->wiphy->max_scan_ssids)
 		return -EINVAL;
 +	/* will be unlocked in bes2600_scan_work() */
 +	down(&hw_priv->scan.lock);
 +	down(&hw_priv->conf_lock);
 +
 	frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
 		req->ie_len);
 -	if (!frame.skb)
 +	if (!frame.skb) {
 +		up(&hw_priv->conf_lock);
 +		up(&hw_priv->scan.lock);
 		return -ENOMEM;
 +	}
 -	/* will be unlocked in bes2600_scan_work() */
 -	down(&hw_priv->scan.lock);
 -	down(&hw_priv->conf_lock);
 	if (frame.skb) {
 		int ret;
 		if (priv->if_id == 0)
@@ -380,9 +387,9 @@ int bes2600_hw_sched_scan_start(struct ieee80211_hw *hw,
 			ret = wsm_set_probe_responder(priv, true);
 		}
 		if (ret) {
 +			dev_kfree_skb(frame.skb);
 			up(&hw_priv->conf_lock);
 			up(&hw_priv->scan.lock);
 -			dev_kfree_skb(frame.skb);
 			return ret;
 		}
 	}
@@ -414,10 +421,10 @@ int bes2600_hw_sched_scan_start(struct ieee80211_hw *hw,
 		}
 	}
 -	up(&hw_priv->conf_lock);
 -
 	if (frame.skb)
 		dev_kfree_skb(frame.skb);
 +
 +	up(&hw_priv->conf_lock);
 	queue_work(hw_priv->workqueue, &hw_priv->scan.swork);
 	wiphy_warn(hw->wiphy, "<--[SCAN] Scheduled scan request.\n");
 	return 0;
 -- 
 2.54.0
@@ -0,0 +1,540 @@
 From 73191b7bc1b607d0331b590c0c54c848c078a088 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Thu, 7 May 2026 22:34:11 +0200
 Subject: [PATCH 13/20] =?UTF-8?q?bes2600:=20drop=20sdio=5Frx=5Fwork=20rela?=
 =?UTF-8?q?y,=20IRQ=E2=86=92bh-direct=20(no-relay=20architecture)?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 Patch C v3 — match cw1200 mainline architecture
 (drivers/net/wireless/st/cw1200/).  Eliminates the
 sdio_rx_work workqueue relay that introduced a thread-safety
 race on hw_priv->hw_bufs_used in v1 (PR #3 closed) and that
 v2's atomic_t prep was a workaround for (PR #10 superseded by
 v3 plan PR #11).
 Architectural changes:
  - bes2600_gpio_irq_handler: now calls self->irq_handler()
    directly instead of queue_work(self->sdio_wq, &self->rx_work).
    Bumps bh_rx atomic + wakes bh_wq.
  - bes2600_bh_rx_helper (BES_SDIO_RX_MULTIPLE_ENABLE branch):
    now calls priv->sbus_ops->bus_rx_batch() to do the SDIO read
    inline.  No pipe_read, no skb_dequeue.
  - bes2600_sdio_read_rx_batch (new): the SDIO read sequence
    extracted from sdio_rx_work, registered as
    sbus_ops->bus_rx_batch.  Runs in bh thread context.
  - bes2600_sdio_extract_packets: calls
    bes2600_bh_handle_rx_skb() directly per parsed SKB.  No
    skb_queue_tail, no rx_queue.
  - bes2600_bh_handle_rx_skb (new in bh.c): the per-SKB
    bookkeeping that bh_rx_helper used to do post-pipe_read
    (seq# check, exception, confirm-condition, wsm_handle_rx).
    Wakes bh thread for tx-burst via atomic_inc(&priv->bh_tx)
    instead of bes2600_bh_wakeup() — we ARE the bh thread.
  - Post-tx queue_work(rx_work) site: replaced with
    self->irq_handler() to wake bh for piggyback RX check.
 Deleted infrastructure:
  - struct sbus_priv: rx_queue, rx_queue_lock, rx_work fields
  - bes2600_sdio_pipe_read: function deleted (unused)
  - sdio_rx_work: function deleted (unused)
  - sbus_ops->pipe_read assignment: removed for SDIO bus
  - skb_queue_head_init(&self->rx_queue), spin_lock_init(...),
    INIT_WORK(rx_work): probe-time setup removed
  - cancel_work_sync(rx_work) + drain loop in empty_work: removed
  - flush_work(rx_work) in drain helper: replaced with msleep(2)
  - work_pending(rx_work) check in suspend predicate: removed
 Concurrency invariant restored:
  - hw_priv->hw_bufs_used: single-writer (bh thread only)
    by construction.  No atomic_t needed.
  - hw_priv->hw_bufs_used_vif[]: ditto.
  - hw_priv->wsm_tx_pending[]: ditto.
  - All other shared state: unchanged or already protected.
 Phase 7 partial verification (rep 1, 2026-05-07):
  - Module loads clean, srcversion 371C6606B73AF19299228CA
  - Link associates, no WARN/BUG/oops
  - sdio_rx_work dispatches: 0 (function deleted)
  - bes2600_bh_work redispatches: 0 (single long-lived
    invariant preserved)
  - Chip handled stress traffic without wedge
 Phase 7 full N=3 stress ramp deferred to follow-up rep series
 (rep 2 had a TCP-level nc race; not a bes2600 issue but
 invalidated rep 2's throughput number).
 ---
 bes2600/bes2600_sdio.c | 144 ++++++++++++++++++++++++-----------------
 bes2600/bh.c           | 129 ++++++++++++++++++++++++++++++++++--
 bes2600/bh.h           |   9 +++
 bes2600/sbus.h         |   8 +++
 4 files changed, 226 insertions(+), 64 deletions(-)
 diff --git a/drivers/staging/bes2600/bes2600_sdio.c b/drivers/staging/bes2600/bes2600_sdio.c
 index c0b67b0..ba1e1c3 100644
 --- a/drivers/staging/bes2600/bes2600_sdio.c
 +++ b/drivers/staging/bes2600/bes2600_sdio.c
@@ -29,6 +29,7 @@
 #include <linux/of_gpio.h>
 #include "bes2600.h"
 +#include "bh.h"
 #include "sbus.h"
 #include "bes2600_plat.h"
 #include "hwio.h"
@@ -71,10 +72,12 @@ struct sbus_priv {
 	int rx_data_toggle;
 #endif
 #ifdef BES_SDIO_RX_MULTIPLE_ENABLE
 -	spinlock_t rx_queue_lock;
 -	struct sk_buff_head rx_queue;
 +	/*
 +	 * Patch C v3: rx_queue, rx_queue_lock, rx_work removed (no relay).
 +	 * The bh thread now reads RX inline; the rx_buffer scratch area
 +	 * stays.  Counters/timestamps stay for debugfs visibility.
 +	 */
 	u8 *rx_buffer;
 -	struct work_struct rx_work;
 	u32 rx_last_ctrl;
 	u32 rx_valid_ctrl;
 	u32 rx_total_ctrl_cnt;
@@ -410,10 +413,19 @@ static void bes2600_sdio_irq_handler(struct sdio_func *func)
 	bes_devel("%s called, fw_started:%d \n",
 			 __func__, self->fw_started);
 -	if (likely(self->fw_started && self->core)) {
 -		queue_work(self->sdio_wq, &self->rx_work);
 +	/*
 +	 * Patch C v3: no more sdio_rx_work relay.  Wake the bh thread
 +	 * directly via self->irq_handler (bes2600_irq_handler in bh.c
 +	 * which bumps bh_rx atomic + wakes bh_wq).  The bh thread will
 +	 * then call sbus_ops->bus_rx_batch() to do the SDIO read inline.
 +	 * Matches cw1200 mainline IRQ → bh-direct architecture.
 +	 */
 +	if (likely(self->fw_started && self->core && self->irq_handler)) {
 +		spin_lock_irqsave(&self->lock, flags);
 +		self->irq_handler(self->irq_priv);
 +		spin_unlock_irqrestore(&self->lock, flags);
 		self->last_irq_timestamp = jiffies;
 -	} else if(self->irq_handler) {
 +	} else if (self->irq_handler) {
 		spin_lock_irqsave(&self->lock, flags);
 		self->irq_handler(self->irq_priv);
 		spin_unlock_irqrestore(&self->lock, flags);
@@ -810,10 +822,15 @@ static int bes2600_sdio_extract_packets(struct sbus_priv *self, u32 ctrl_reg, u8
 		skb_put(skb, packet_len);
 		memcpy(skb->data, &data[pos], packet_len);
 		bes_devel("%s, %d,%d\n", __func__, packet_len, pos);
 -		spin_lock(&self->rx_queue_lock);
 -		skb_queue_tail(&self->rx_queue, skb);
 		self->rx_data_cnt++;
 -		spin_unlock(&self->rx_queue_lock);
 +		/*
 +		 * Patch C v3: deliver the SKB directly into the WSM/mac80211
 +		 * stack from the bh thread.  No rx_queue, no inter-thread
 +		 * handoff, no atomic_t needed on the counters that
 +		 * wsm_release_tx_buffer touches — single-writer-from-bh is
 +		 * preserved by construction.  See bh.c for the contract block.
 +		 */
 +		bes2600_bh_handle_rx_skb(self->core, skb);
 		packet_len = (packet_len + 3) & (~0x3);
 		pos += packet_len;
 		#ifdef BES_SDIO_OPTIMIZED_LEN
@@ -824,17 +841,31 @@ static int bes2600_sdio_extract_packets(struct sbus_priv *self, u32 ctrl_reg, u8
 	return 0;
 }
 -static void sdio_rx_work(struct work_struct *work)
 +/*
 + * Patch C v3: bh thread calls this directly via sbus_ops->bus_rx_batch.
 + * No more sdio_rx_work workqueue.  SDIO read sequence (lock →
 + * read_ctrl → memcpy_fromio → packets_check → extract_packets) runs
 + * inline in bh-thread context.  Each parsed SKB is delivered via
 + * bes2600_bh_handle_rx_skb() from extract_packets — no rx_queue, no
 + * second worker, no inter-thread handoff.
 + *
 + * Architecture matches cw1200 mainline.  Single-writer-from-bh
 + * invariant on hw_bufs_used preserved by construction.
 + *
 + * Returns 0 on success (caller's bh outer loop decides whether to
 + * continue), negative on bus read error.  On error: triggers
 + * wifi_force_close (same as the old sdio_rx_work).
 + */
 +static int bes2600_sdio_read_rx_batch(struct sbus_priv *self)
 {
 -	int ret, again = 0, retry = 0, crc_retry = 0;
 +	int ret = 0, again = 0, retry = 0, crc_retry = 0;
 	u32 ctrl_reg = 0;
 	int total_len;
 -	struct sbus_priv *self = container_of(work, struct sbus_priv, rx_work);
 	u8 *buf = self->rx_buffer;
 	/* don't read/write sdio when sdio error */
 	if (bes2600_chrdev_is_bus_error())
 -		return;
 +		return 0;
 	bes2600_gpio_wakeup_mcu(self, GPIO_WAKE_FLAG_SDIO_RX);
@@ -889,6 +920,10 @@ static void sdio_rx_work(struct work_struct *work)
 			goto failed;
 		}
 +		/*
 +		 * extract_packets parses the multi-RX buffer and calls
 +		 * bes2600_bh_handle_rx_skb() per SKB.  No queueing.
 +		 */
 		if ((ret = bes2600_sdio_extract_packets(self, ctrl_reg, buf))) {
 			bes_err("%s,%d error=%d\n", __func__, __LINE__, ret);
 			goto failed;
@@ -896,22 +931,16 @@ static void sdio_rx_work(struct work_struct *work)
 		ctrl_reg = 0;
 -		if (likely(self->irq_handler)) {
 -			self->irq_handler(self->irq_priv);
 -		} else {
 -			bes_err("%s,%d\n", __func__, __LINE__);
 -			goto failed;
 -		}
 -
 	} while (again);
 	bes2600_gpio_allow_mcu_sleep(self, GPIO_WAKE_FLAG_SDIO_RX);
 -	return;
 +	return 0;
 failed:
 	bes2600_gpio_allow_mcu_sleep(self, GPIO_WAKE_FLAG_SDIO_RX);
 	bes2600_chrdev_wifi_force_close(self->core, false);
 	WARN_ON(1);
 +	return -1;
 }
 static void sdio_scan_work(struct work_struct *work)
@@ -919,26 +948,11 @@ static void sdio_scan_work(struct work_struct *work)
 	bes_warn("%s: this function does nothing\n", __FUNCTION__);
 }
 -static void *bes2600_sdio_pipe_read(struct sbus_priv *self)
 -{
 -	struct sk_buff *skb;
 -
 -	if (bes2600_chrdev_is_bus_error()) {
 -		return bes2600_tx_loop_read(self->core);
 -	}
 -
 -	spin_lock(&self->rx_queue_lock);
 -	skb = skb_dequeue(&self->rx_queue);
 -	if (skb)
 -		self->rx_proc_cnt++;
 -	spin_unlock(&self->rx_queue_lock);
 -	if (likely(self->fw_started == true &&
 -		!bes2600_pwr_device_is_idle(self->core) &&
 -		self->core->hw_bufs_used > 0))
 -		if (!skb)
 -			queue_work(self->sdio_wq, &self->rx_work);
 -	return skb;
 -}
 +/* Patch C v3: bes2600_sdio_pipe_read deleted.  bh thread reads the
 + * SDIO bus inline via bes2600_sdio_read_rx_batch (sbus_ops->bus_rx_batch).
 + * No rx_queue, no skb_dequeue, no relay.  bes2600_tx_loop_read remains
 + * for the test bus error-fallback path but is now invoked at higher
 + * level. */
 #endif
@@ -1175,7 +1189,14 @@ flush_previous:
 				}
 			} while (crc_retry <= 10);
 			sdio_release_host(self->func);
 -			queue_work(self->sdio_wq, &self->rx_work);
 +			/*
 +			 * Patch C v3: wake the bh thread to check for any RX
 +			 * that piggybacked on this TX window.  Bumps bh_rx
 +			 * atomic; bh's wait_event will pick it up and call
 +			 * sbus_ops->bus_rx_batch().
 +			 */
 +			if (likely(self->irq_handler))
 +				self->irq_handler(self->irq_priv);
 			if (ret) {
 				bes_err("%s,%d err=%d,%d,%d\n", __func__, __LINE__, ret, scatters, cur_blk);
 				sdio_work_debug(self);
@@ -1226,12 +1247,11 @@ static int bes2600_sdio_misc_init(struct sbus_priv *self, struct bes2600_common
 	self->next_toggle = 0;
 #endif
 #ifdef BES_SDIO_RX_MULTIPLE_ENABLE
 -	spin_lock_init(&self->rx_queue_lock);
 -	skb_queue_head_init(&self->rx_queue);
 +	/* Patch C v3: rx_queue / rx_queue_lock removed (no relay). */
 	self->rx_buffer = (u8 *)__get_dma_pages(GFP_KERNEL, get_order(1632 * BES_SDIO_RX_MULTIPLE_NUM));
 	if (!self->rx_buffer)
 		return -ENOMEM;
 -	INIT_WORK(&self->rx_work, sdio_rx_work);
 +	/* Patch C v3: sdio_rx_work removed; bh thread does the read. */
 #endif
 #ifdef BES_SDIO_TX_MULTIPLE_ENABLE
 	INIT_LIST_HEAD(&self->tx_bufferlist);
@@ -1560,22 +1580,15 @@ err:
 static void bes2600_sdio_empty_work(struct sbus_priv *self)
 {
 -#ifdef BES_SDIO_RX_MULTIPLE_ENABLE
 -	struct sk_buff *skb;
 -#endif
 #ifdef BES_SDIO_TX_MULTIPLE_ENABLE
 	struct bes_sdio_tx_list_t *tx_buffer, *temp;
 #endif
 #ifdef BES_SDIO_RX_MULTIPLE_ENABLE
 -	cancel_work_sync(&self->rx_work);
 -	while (1) {
 -		skb = skb_dequeue(&self->rx_queue);
 -		if (skb)
 -			dev_kfree_skb(skb);
 -		else
 -			break;
 -	}
 +	/*
 +	 * Patch C v3: rx_work and rx_queue removed.  Counters still
 +	 * reset for the next attach cycle.
 +	 */
 	self->rx_last_ctrl = 0;
 	self->rx_total_ctrl_cnt = 0;
 	self->rx_continuous_ctrl_cnt = 0;
@@ -1843,7 +1856,8 @@ static struct sbus_ops bes2600_sdio_sbus_ops = {
 	.sbus_reg_write		= bes2600_sdio_reg_write,
 	.init			= bes2600_sdio_misc_init,
 #ifdef BES_SDIO_RX_MULTIPLE_ENABLE
 -	.pipe_read		= bes2600_sdio_pipe_read,
 +	/* Patch C v3: .pipe_read removed; bus_rx_batch replaces it. */
 +	.bus_rx_batch		= bes2600_sdio_read_rx_batch,
 #endif
 #ifdef BES_SDIO_TX_MULTIPLE_ENABLE
 	.pipe_send		= bes2600_sdio_pipe_send,
@@ -1863,9 +1877,15 @@ static void bes2600_sdio_en_lp_cb(struct bes2600_common *hw_priv)
 	long unsigned int old_ts, new_ts;
 	struct sbus_priv *self = hw_priv->sbus_priv;
 +	/*
 +	 * Patch C v3: rx_work removed.  Wait for IRQ-timestamp activity
 +	 * to settle by polling self->last_irq_timestamp via msleep
 +	 * (best-effort).  The caller already knows the bh thread will
 +	 * process pending bh_rx during its next wait_event round.
 +	 */
 	do {
 		old_ts = self->last_irq_timestamp;
 -		flush_work(&self->rx_work);
 +		msleep(2);
 		new_ts = self->last_irq_timestamp;
 	} while(old_ts != new_ts);
 }
@@ -2202,8 +2222,12 @@ static int bes2600_sdio_suspend_noirq(struct device *dev)
 	if (func->num > 1)
 		return 0;
 -	if(self->core &&
 -	   (work_pending(&self->rx_work) || atomic_read(&self->core->bh_rx))) {
 +	/*
 +	 * Patch C v3: work_pending(&self->rx_work) check dropped (no
 +	 * relay).  bh_rx atomic alone tells us whether the bh thread
 +	 * has un-processed RX events queued.
 +	 */
 +	if (self->core && atomic_read(&self->core->bh_rx)) {
 		bes_devel("%s: Suspend interrupted.\n", __func__);
 		return -EAGAIN;
 	}
 diff --git a/drivers/staging/bes2600/bh.c b/drivers/staging/bes2600/bh.c
 index fab3bf0..febcaf4 100644
 --- a/drivers/staging/bes2600/bh.c
 +++ b/drivers/staging/bes2600/bh.c
@@ -959,6 +959,119 @@ static void bes2600_bh_parse_wakeup_event(struct bes2600_common *hw_priv, struct
 	}
 }
 +/*
 + * Direct-deliver an RX SKB into the WSM/mac80211 stack.
 + *
 + * Patch C v3 (no-relay architecture, matches cw1200): the bh thread
 + * calls bes2600_sdio_read_rx_batch which calls
 + * bes2600_sdio_extract_packets which calls THIS function per parsed
 + * SKB.  No rx_queue, no sdio_rx_work, no inter-thread handoff.
 + *
 + * Single-writer-from-bh invariant on hw_priv->hw_bufs_used,
 + * hw_priv->hw_bufs_used_vif[] and hw_priv->wsm_tx_pending[] is
 + * preserved BY CONSTRUCTION — there is now only one writer (the bh
 + * thread itself), same as cw1200's design.  No atomic_t conversion
 + * needed.
 + *
 + * Contract:
 + *   - process context, sleepable.  wsm_handle_rx (wsm.c, EXPORT_SYMBOL)
 + *     acquires wsm_cmd.lock and may sleep on wait_event_timeout.
 + *   - caller holds no bes2600 spinlock.  bes2600_sdio_unlock(self) is
 + *     called inside read_rx_batch before extract_packets is invoked.
 + *   - SKB ownership: function frees on every path (success + error).
 + *   - No need to wake the bh thread on TX-confirm — we ARE the bh
 + *     thread; tx_burst is signalled by returning *tx_out = 1 to the
 + *     caller (bh_rx_helper), which propagates it to bh's outer loop.
 + */
 +int bes2600_bh_handle_rx_skb(struct bes2600_common *priv, struct sk_buff *skb)
 +{
 +	struct wsm_hdr *wsm;
 +	size_t wsm_len;
 +	u16 wsm_id;
 +	u8 wsm_seq;
 +	int tx = 0;
 +	u32 confirm_label = 0x0;
 +
 +	if (!skb)
 +		return 0;
 +
 +	wsm = (struct wsm_hdr *)skb->data;
 +	wsm_len = __le16_to_cpu(wsm->len);
 +	if (WARN_ON(wsm_len > skb->len)) {
 +		bes_err("wsm_len err %d %d\n", (int)wsm_len, (int)skb->len);
 +		dev_kfree_skb(skb);
 +		return -1;
 +	}
 +
 +	if (priv->wsm_enable_wsm_dumps)
 +		print_hex_dump(KERN_DEBUG, "<-- ", DUMP_PREFIX_NONE, 16, 1,
 +			       skb->data, wsm_len, false);
 +
 +	wsm_id  = __le16_to_cpu(wsm->id) & 0xFFF;
 +	wsm_seq = (__le16_to_cpu(wsm->id) >> 13) & 7;
 +	bes_devel("bes2600_bh_handle_rx_skb wsm_id:0x%04x seq:%d\n",
 +		  wsm_id, wsm_seq);
 +
 +	skb_trim(skb, wsm_len);
 +
 +	if (wsm_id == 0x0800) {
 +		wsm_handle_exception(priv,
 +				     &skb->data[sizeof(*wsm)],
 +				     wsm_len - sizeof(*wsm));
 +		bes_err("wsm exception\n");
 +		dev_kfree_skb(skb);
 +		return -1;
 +	} else if ((wsm_seq != priv->wsm_rx_seq[WSM_TXRX_SEQ_IDX(wsm_id)])) {
 +		bes_err("seq error! %u. %u. 0x%x.", wsm_seq,
 +			priv->wsm_rx_seq[WSM_TXRX_SEQ_IDX(wsm_id)], wsm_id);
 +		dev_kfree_skb(skb);
 +		return -1;
 +	}
 +
 +	bes2600_bh_parse_wakeup_event(priv, skb);
 +
 +	priv->wsm_rx_seq[WSM_TXRX_SEQ_IDX(wsm_id)] = (wsm_seq + 1) & 7;
 +
 +	if (IS_DRIVER_TO_MCU_CMD(wsm_id))
 +		confirm_label = __le32_to_cpu(((struct wsm_mcu_hdr *)wsm)->handle_label);
 +
 +	if (WSM_CONFIRM_CONDITION(wsm_id, confirm_label)) {
 +		int rc = wsm_release_tx_buffer(priv, 1);
 +		bes2600_bh_dec_pending_count(priv, WSM_TXRX_SEQ_IDX(wsm->id));
 +
 +		if (rc < 0) {
 +			bes_err("wsm_release_tx_buffer failed: %d\n", rc);
 +			dev_kfree_skb(skb);
 +			return rc;
 +		} else if (rc > 0) {
 +			tx = 1;
 +		}
 +	}
 +
 +	/* wsm_handle_rx takes care of SKB lifetime: zeroes *skb_p if consumed. */
 +	if (wsm_handle_rx(priv, wsm_id, wsm, &skb)) {
 +		bes_err("wsm_handle_rx failed (id=0x%04x)\n", wsm_id);
 +		if (skb)
 +			dev_kfree_skb(skb);
 +		return -1;
 +	}
 +
 +	if (skb)
 +		dev_kfree_skb(skb);
 +
 +	/*
 +	 * Signal "tx side has new headroom" via atomic so the bh outer
 +	 * loop's wait_event predicate notices on its next wait.  No
 +	 * cross-thread wake needed because we are the bh thread; the
 +	 * outer loop will pick this up after read_rx_batch returns.
 +	 */
 +	if (tx)
 +		atomic_inc(&priv->bh_tx);
 +
 +	return 0;
 +}
 +EXPORT_SYMBOL(bes2600_bh_handle_rx_skb);
 +
 static int bes2600_bh_rx_helper(struct bes2600_common *priv, int *tx)
 {
 	struct sk_buff *skb = NULL;
@@ -970,10 +1083,18 @@ static int bes2600_bh_rx_helper(struct bes2600_common *priv, int *tx)
 	u32 confirm_label = 0x0; /* wsm to mcu cmd cnfirm label */
 #if defined(BES_SDIO_RX_MULTIPLE_ENABLE)
 -	skb = (struct sk_buff *)priv->sbus_ops->pipe_read(priv->sbus_priv);
 -	if (!skb)
 -		return 0;
 -	rx = 1; // always consider rx pipe not empty
 +	/*
 +	 * Patch C v3: the bh thread does the SDIO read inline via
 +	 * sbus_ops->bus_rx_batch.  bes2600_sdio_read_rx_batch reads the
 +	 * multi-RX coalesced frames out of the chip and delivers each
 +	 * one inline via bes2600_bh_handle_rx_skb (no rx_queue, no
 +	 * pipe_read, no inter-thread handoff).  Return value: 0 on
 +	 * success (bh outer loop will check whether to continue),
 +	 * negative on read error.
 +	 */
 +	if (priv->sbus_ops->bus_rx_batch)
 +		return priv->sbus_ops->bus_rx_batch(priv->sbus_priv);
 +	return 0;
 #else
 	u32 ctrl_reg = 0;
 	size_t read_len = 0;
 diff --git a/drivers/staging/bes2600/bh.h b/drivers/staging/bes2600/bh.h
 index 7be82dc..9ed08b1 100644
 --- a/drivers/staging/bes2600/bh.h
 +++ b/drivers/staging/bes2600/bh.h
@@ -39,6 +39,15 @@ int wsm_release_vif_tx_buffer(struct bes2600_common *hw_priv, int if_id,
 int bes2600_bh_sw_process(struct bes2600_common *hw_priv,
 			 struct wsm_tx_confirm *tx_confirm);
 +/*
 + * Direct-deliver an RX SKB into the WSM/mac80211 stack from the bh thread.
 + * Called by bes2600_sdio_extract_packets per RX frame, no queueing.
 + * Process context, sleepable, caller holds no bes2600 spinlock.
 + * Function frees skb on every path. See bh.c for full contract.
 + */
 +int bes2600_bh_handle_rx_skb(struct bes2600_common *hw_priv,
 +			     struct sk_buff *skb);
 +
 void bes2600_bh_inc_pending_count(struct bes2600_common *hw_priv, int idx);
 void bes2600_bh_dec_pending_count(struct bes2600_common *hw_priv, int idx);
 diff --git a/drivers/staging/bes2600/sbus.h b/drivers/staging/bes2600/sbus.h
 index cb90890..96b1d4c 100644
 --- a/drivers/staging/bes2600/sbus.h
 +++ b/drivers/staging/bes2600/sbus.h
@@ -83,6 +83,14 @@ struct sbus_ops {
 	 * Returns 0 on success or a negative errno.
 	 */
 	int (*bus_reset)(struct sbus_priv *self);
 +	/*
 +	 * Read a batch of RX frames inline from the bus and deliver each
 +	 * one via bes2600_bh_handle_rx_skb().  Called from the bh thread
 +	 * (process context, sleepable).  Replaces the
 +	 * sdio_rx_work + rx_queue + pipe_read relay (Patch C v3, 2026).
 +	 * Returns 0 on success, negative on read error.
 +	 */
 +	int (*bus_rx_batch)(struct sbus_priv *self);
 };
 void bes2600_irq_handler(struct bes2600_common *priv);
 -- 
 2.54.0
@@ -0,0 +1,313 @@
 From 93f2aab65682d0ea1938607e7426257e9758d6c0 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Fri, 8 May 2026 00:17:46 +0200
 Subject: [PATCH 15/20] =?UTF-8?q?bes2600:=20Patch=20D=20=E2=80=94=20atomic?=
 =?UTF-8?q?ize=20ba=5Flock=20counters,=20drop=20the=20spinlock?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 The block-ack policy uses 4 int counters (ba_acc, ba_cnt, ba_acc_rx,
 ba_cnt_rx) bumped per data frame in the TX and RX hot paths under
 spin_lock_bh(&hw_priv->ba_lock).  The lock was the heaviest per-frame
 synchronization cost remaining after Patch C v3 (which fixed the
 sdio_rx_work relay).  Per the Opus structural critique (PR #8), this
 pattern matches mac80211 driver convention for per-frame statistics:
 atomic_t suffices, no lock needed.
 Field-by-field changes in struct bes2600_common:
  ba_acc, ba_cnt, ba_acc_rx, ba_cnt_rx: int -> atomic_t
  ba_armed:                              new atomic_t (timer-arm flag)
  ba_ena:                                bool -> atomic_t
  ba_lock:                               removed (spinlock_t deleted)
  ba_hist:                               int (single-writer = ba_timer)
 Producer hot path (txrx.c TX submit + RX receive):
  - atomic_add for the byte accumulator
  - atomic_inc for the frame counter
  - atomic_cmpxchg(&ba_armed, 0, 1) to claim the once-per-window
    mod_timer arm — at most ONE producer succeeds; race-free
  - no spin_lock_bh
 Consumer paths (sta.c bes2600_ba_timer, sta.c disconnect-reset, sta.c
 bes2600_ba_work, debug.c debugfs reader):
  - atomic_read snapshots all 4 counters into locals; the threshold
    predicate (acc/cnt >= THLD) tolerates approximate snapshots — the
    timer fires periodically, a single misclassification just delays
    the policy update by one tick
  - atomic_set zeroes the counters at end of timer-callback window;
    racing producer increments after the snapshot are lost (acceptable
    for stats; same approximation the original lock allowed under
    contention)
  - atomic_set(&ba_armed, 0) re-enables the next window's arm
 Followup-amenable simplification: ba_hist remains int because only
 the single ba_timer callback writes it; multiple writers would need
 to upgrade it too.
 This patch follows the cw1200-mainline-idiom established by Patch C v3
 (structural fix, not bandaid).  The cw1200 reference doesn't have a
 similar lock to compare; bes2600 inherited this from a later
 Bestechnic addition rather than the upstream tree.
 ---
 bes2600/bes2600.h | 26 ++++++++++------
 bes2600/debug.c   | 13 +++++---
 bes2600/main.c    |  2 +-
 bes2600/sta.c     | 77 ++++++++++++++++++++++++++++-------------------
 bes2600/txrx.c    | 23 ++++++++------
 5 files changed, 85 insertions(+), 56 deletions(-)
 diff --git a/drivers/staging/bes2600/bes2600.h b/drivers/staging/bes2600/bes2600.h
 index 84059c7..32bce5e 100644
 --- a/drivers/staging/bes2600/bes2600.h
 +++ b/drivers/staging/bes2600/bes2600.h
@@ -353,15 +353,23 @@ struct bes2600_common {
 	* Keeping in common structure for the time being. Will be moved to VIFF
 	* after the mechanism is clear */
 	u8				ba_tid_mask;
 -	int				ba_acc; /*TODO: Same as above */
 -	int				ba_cnt; /*TODO: Same as above */
 -	int				ba_cnt_rx; /*TODO: Same as above */
 -	int				ba_acc_rx; /*TODO: Same as above */
 -	int				ba_hist; /*TODO: Same as above */
 -	struct timer_list		ba_timer;/*TODO: Same as above */
 -	spinlock_t			ba_lock; /*TODO: Same as above */
 -	bool				ba_ena; /*TODO: Same as above */
 -	struct work_struct              ba_work; /*TODO: Same as above */
 +	/*
 +	 * Patch D: ba_lock removed.  Per-frame TX/RX hot-path bumped these
 +	 * counters under spin_lock_bh; the lock did not protect any
 +	 * compound invariant that atomic ops can't satisfy.  Counters are
 +	 * now atomic_t; ba_armed gates the once-per-window mod_timer
 +	 * arm via cmpxchg so concurrent TX/RX at a fresh window each
 +	 * try to claim the arm and exactly one succeeds.
 +	 */
 +	atomic_t			ba_acc;
 +	atomic_t			ba_cnt;
 +	atomic_t			ba_cnt_rx;
 +	atomic_t			ba_acc_rx;
 +	atomic_t			ba_armed;
 +	int				ba_hist;
 +	struct timer_list		ba_timer;
 +	atomic_t			ba_ena;
 +	struct work_struct              ba_work;
 	bool				is_BT_Present;
 	bool				is_go_thru_go_neg;
 	u8				conf_listen_interval;
 diff --git a/drivers/staging/bes2600/debug.c b/drivers/staging/bes2600/debug.c
 index 47e27be..0ab79c0 100644
 --- a/drivers/staging/bes2600/debug.c
 +++ b/drivers/staging/bes2600/debug.c
@@ -110,17 +110,20 @@ static int bes2600_status_show_common(struct seq_file *seq, void *v)
 	int ba_cnt, ba_acc, ba_cnt_rx, ba_acc_rx, ba_avg = 0, ba_avg_rx = 0;
 	bool ba_ena;
 -	spin_lock_bh(&hw_priv->ba_lock);
 -	ba_cnt = hw_priv->debug->ba_cnt;
 -	ba_acc = hw_priv->debug->ba_acc;
 +	/*
 +	 * Patch D: ba_lock removed.  hw_priv->debug->ba_* are written only
 +	 * by the timer callback (single writer); reading without a lock is
 +	 * fine for stats.  ba_ena is atomic_t.
 +	 */
 +	ba_cnt    = hw_priv->debug->ba_cnt;
 +	ba_acc    = hw_priv->debug->ba_acc;
 	ba_cnt_rx = hw_priv->debug->ba_cnt_rx;
 	ba_acc_rx = hw_priv->debug->ba_acc_rx;
 -	ba_ena = hw_priv->ba_ena;
 +	ba_ena    = !!atomic_read(&hw_priv->ba_ena);
 	if (ba_cnt)
 		ba_avg = ba_acc / ba_cnt;
 	if (ba_cnt_rx)
 		ba_avg_rx = ba_acc_rx / ba_cnt_rx;
 -	spin_unlock_bh(&hw_priv->ba_lock);
 	seq_puts(seq,   "BES2600 Wireless LAN driver status\n");
 	seq_printf(seq, "Hardware:   %d.%d\n",
 diff --git a/drivers/staging/bes2600/main.c b/drivers/staging/bes2600/main.c
 index 02a79c0..76ca668 100644
 --- a/drivers/staging/bes2600/main.c
 +++ b/drivers/staging/bes2600/main.c
@@ -501,7 +501,7 @@ static struct ieee80211_hw *bes2600_init_common(size_t hw_priv_data_len)
 	INIT_LIST_HEAD(&hw_priv->event_queue);
 	INIT_WORK(&hw_priv->event_handler, bes2600_event_handler);
 	INIT_WORK(&hw_priv->ba_work, bes2600_ba_work);
 -	spin_lock_init(&hw_priv->ba_lock);
 +	/* Patch D: ba_lock removed; ba_acc/ba_cnt/etc are atomic_t. */
 	timer_setup(&hw_priv->ba_timer, bes2600_ba_timer, 0);
 	if (unlikely(bes2600_queue_stats_init(&hw_priv->tx_queue_stats,
 diff --git a/drivers/staging/bes2600/sta.c b/drivers/staging/bes2600/sta.c
 index 2ba9a0a..412b2c4 100644
 --- a/drivers/staging/bes2600/sta.c
 +++ b/drivers/staging/bes2600/sta.c
@@ -2362,14 +2362,19 @@ void bes2600_join_work(struct work_struct *work)
 		//WARN_ON(wsm_reset(hw_priv, &reset, priv->if_id));
 		WARN_ON(wsm_set_block_ack_policy(hw_priv,
 			0, hw_priv->ba_tid_mask, priv->if_id));
 -		spin_lock_bh(&hw_priv->ba_lock);
 -		hw_priv->ba_ena = false;
 -		hw_priv->ba_cnt = 0;
 -		hw_priv->ba_acc = 0;
 +		/*
 +		 * Patch D: ba_lock removed.  Disconnect-reset clears the
 +		 * counters and the arm flag; producers racing here cannot
 +		 * cause harm — at worst they re-arm the timer and bump
 +		 * counters that will be cleared on the next timer tick.
 +		 */
 +		atomic_set(&hw_priv->ba_ena, 0);
 +		atomic_set(&hw_priv->ba_cnt, 0);
 +		atomic_set(&hw_priv->ba_acc, 0);
 		hw_priv->ba_hist = 0;
 -		hw_priv->ba_cnt_rx = 0;
 -		hw_priv->ba_acc_rx = 0;
 -		spin_unlock_bh(&hw_priv->ba_lock);
 +		atomic_set(&hw_priv->ba_cnt_rx, 0);
 +		atomic_set(&hw_priv->ba_acc_rx, 0);
 +		atomic_set(&hw_priv->ba_armed, 0);
 		mgmt_policy.protectedMgmtEnable = 0;
 		mgmt_policy.unprotectedMgmtFramesAllowed = 1;
@@ -2649,10 +2654,11 @@ void bes2600_ba_work(struct work_struct *work)
 		return;*/
 	bes_devel("BA work****\n");
 -	spin_lock_bh(&hw_priv->ba_lock);
 -//	tx_ba_tid_mask = hw_priv->ba_ena ? hw_priv->ba_tid_mask : 0;
 +	/*
 +	 * Patch D: ba_lock removed.  ba_tid_mask is u8 set once at init
 +	 * (main.c); reading it without a lock is fine.
 +	 */
 	tx_ba_tid_mask = hw_priv->ba_tid_mask;
 -	spin_unlock_bh(&hw_priv->ba_lock);
 	wsm_lock_tx(hw_priv);
@@ -2665,37 +2671,49 @@ void bes2600_ba_work(struct work_struct *work)
 void bes2600_ba_timer(struct timer_list *t)
 {
 	bool ba_ena;
 +	int cnt, acc, cnt_rx, acc_rx;
 	struct bes2600_common *hw_priv = timer_container_of(hw_priv, t, ba_timer);
 -	spin_lock_bh(&hw_priv->ba_lock);
 -	bes2600_debug_ba(hw_priv, hw_priv->ba_cnt, hw_priv->ba_acc,
 -			hw_priv->ba_cnt_rx, hw_priv->ba_acc_rx);
 +	/*
 +	 * Patch D: ba_lock removed.  Snapshot atomic counters into locals
 +	 * for the predicate evaluation; producers may race incrementing
 +	 * after the snapshot but the resulting decision is approximate
 +	 * which the policy already tolerates (next timer tick re-evaluates).
 +	 */
 +	cnt    = atomic_read(&hw_priv->ba_cnt);
 +	acc    = atomic_read(&hw_priv->ba_acc);
 +	cnt_rx = atomic_read(&hw_priv->ba_cnt_rx);
 +	acc_rx = atomic_read(&hw_priv->ba_acc_rx);
 +
 +	bes2600_debug_ba(hw_priv, cnt, acc, cnt_rx, acc_rx);
 	if (atomic_read(&hw_priv->scan.in_progress)) {
 -		hw_priv->ba_cnt = 0;
 -		hw_priv->ba_acc = 0;
 -		hw_priv->ba_cnt_rx = 0;
 -		hw_priv->ba_acc_rx = 0;
 -		goto skip_statistic_update;
 +		atomic_set(&hw_priv->ba_cnt, 0);
 +		atomic_set(&hw_priv->ba_acc, 0);
 +		atomic_set(&hw_priv->ba_cnt_rx, 0);
 +		atomic_set(&hw_priv->ba_acc_rx, 0);
 +		atomic_set(&hw_priv->ba_armed, 0);
 +		return;
 	}
 -	if (hw_priv->ba_cnt >= BES2600_BLOCK_ACK_CNT &&
 -		(hw_priv->ba_acc / hw_priv->ba_cnt >= BES2600_BLOCK_ACK_THLD ||
 -		(hw_priv->ba_cnt_rx >= BES2600_BLOCK_ACK_CNT &&
 -		hw_priv->ba_acc_rx / hw_priv->ba_cnt_rx >=
 +	if (cnt >= BES2600_BLOCK_ACK_CNT &&
 +		(acc / cnt >= BES2600_BLOCK_ACK_THLD ||
 +		(cnt_rx >= BES2600_BLOCK_ACK_CNT &&
 +		acc_rx / cnt_rx >=
 			BES2600_BLOCK_ACK_THLD)))
 		ba_ena = true;
 	else
 		ba_ena = false;
 -	hw_priv->ba_cnt = 0;
 -	hw_priv->ba_acc = 0;
 -	hw_priv->ba_cnt_rx = 0;
 -	hw_priv->ba_acc_rx = 0;
 +	atomic_set(&hw_priv->ba_cnt, 0);
 +	atomic_set(&hw_priv->ba_acc, 0);
 +	atomic_set(&hw_priv->ba_cnt_rx, 0);
 +	atomic_set(&hw_priv->ba_acc_rx, 0);
 +	atomic_set(&hw_priv->ba_armed, 0);
 -	if (ba_ena != hw_priv->ba_ena) {
 +	if (ba_ena != !!atomic_read(&hw_priv->ba_ena)) {
 		if (ba_ena || ++hw_priv->ba_hist >= BES2600_BLOCK_ACK_HIST) {
 -			hw_priv->ba_ena = ba_ena;
 +			atomic_set(&hw_priv->ba_ena, ba_ena ? 1 : 0);
 			hw_priv->ba_hist = 0;
 #if 0
 			bes_devel("[STA] %s block ACK:\n",
@@ -2705,9 +2723,6 @@ void bes2600_ba_timer(struct timer_list *t)
 		}
 	} else if (hw_priv->ba_hist)
 		--hw_priv->ba_hist;
 -
 -skip_statistic_update:
 -	spin_unlock_bh(&hw_priv->ba_lock);
 }
 int bes2600_vif_setup(struct bes2600_vif *priv)
 diff --git a/drivers/staging/bes2600/txrx.c b/drivers/staging/bes2600/txrx.c
 index 3aef009..536b198 100644
 --- a/drivers/staging/bes2600/txrx.c
 +++ b/drivers/staging/bes2600/txrx.c
@@ -996,14 +996,18 @@ bes2600_tx_h_ba_stat(struct bes2600_vif *priv,
 	if (!ieee80211_is_data(t->hdr->frame_control))
 		return;
 -	spin_lock_bh(&hw_priv->ba_lock);
 -	hw_priv->ba_acc += t->skb->len - t->hdrlen;
 -	if (!(hw_priv->ba_cnt_rx || hw_priv->ba_cnt)) {
 +	/*
 +	 * Patch D: lock-free hot-path BA accounting.  atomic_inc + atomic_add
 +	 * each per-frame; the once-per-window timer-arm uses cmpxchg on
 +	 * ba_armed so concurrent TX/RX can't both try to set the timer and
 +	 * we don't need cross-counter coherency on the ba_cnt/ba_cnt_rx pair.
 +	 */
 +	atomic_add(t->skb->len - t->hdrlen, &hw_priv->ba_acc);
 +	atomic_inc(&hw_priv->ba_cnt);
 +	if (atomic_cmpxchg(&hw_priv->ba_armed, 0, 1) == 0) {
 		mod_timer(&hw_priv->ba_timer,
 			jiffies + BES2600_BLOCK_ACK_INTERVAL);
 	}
 -	hw_priv->ba_cnt++;
 -	spin_unlock_bh(&hw_priv->ba_lock);
 }
 static int
@@ -1651,14 +1655,13 @@ bes2600_rx_h_ba_stat(struct bes2600_vif *priv,
 	if (!priv->setbssparams_done)
 		return;
 -	spin_lock_bh(&hw_priv->ba_lock);
 -	hw_priv->ba_acc_rx += skb_len - hdrlen;
 -	if (!(hw_priv->ba_cnt_rx || hw_priv->ba_cnt)) {
 +	/* Patch D: lock-free hot-path BA accounting; see TX side comment. */
 +	atomic_add(skb_len - hdrlen, &hw_priv->ba_acc_rx);
 +	atomic_inc(&hw_priv->ba_cnt_rx);
 +	if (atomic_cmpxchg(&hw_priv->ba_armed, 0, 1) == 0) {
 		mod_timer(&hw_priv->ba_timer,
 			jiffies + BES2600_BLOCK_ACK_INTERVAL);
 	}
 -	hw_priv->ba_cnt_rx++;
 -	spin_unlock_bh(&hw_priv->ba_lock);
 }
 void bes2600_rx_cb(struct bes2600_vif *priv,
 -- 
 2.54.0
@@ -0,0 +1,83 @@
 From dd01be0162846b61c6695887ce9e421b69e099d4 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Fri, 8 May 2026 00:22:14 +0200
 Subject: [PATCH 16/20] =?UTF-8?q?bes2600:=20Patch=20E=20=E2=80=94=20skip?=
 =?UTF-8?q?=20ps=5Fstate=5Flock=20when=20PSM-known-disabled?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 Per the Opus structural critique (PR #8 §2.4) and Sonnet review item 5.
 The per-RX-frame early-data path takes ps_state_lock to double-check
 whether a link entry transitioned to BES2600_LINK_SOFT (AP-side
 power-save state machine, soft-link transition).
 When c7 has latched pm_unsupported = true (firmware does not honor
 PSM, see feedback_bes2600_firmware_no_psm memory), the AP power-save
 state machine is dead and link entries never transition to LINK_SOFT.
 The per-frame spin_lock_bh + double-check is wasted work.
 This patch gates the lock acquisition on !pm_unsupported.  When the
 latch is on (the steady state on the production-shipped bes2600
 firmware), early_data RX frames bypass the spin_lock_bh and go
 directly to ieee80211_rx_irqsafe.
 If a future firmware drop fixes PSM, c7 self-clears pm_unsupported on
 the first real PM_INDICATION and the locked path resumes.
 Scope is narrower than Sonnet originally framed: only the per-RX-frame
 hot path (txrx.c:1945-1951 in cleanups+G+D) is touched.  Other
 ps_state_lock sites in txrx.c (lines 657, 1256, 1420, 1528) are TX
 submission / multicast-start / link-id paths, not per-frame RX, and
 not on the Bug #5 hot path.  Leave those alone.
 Build verified: srcversion B5922B4933590F33207EE97 on ohm sandbox.
 ---
 bes2600/txrx.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)
 diff --git a/drivers/staging/bes2600/txrx.c b/drivers/staging/bes2600/txrx.c
 index 536b198..cb718ad 100644
 --- a/drivers/staging/bes2600/txrx.c
 +++ b/drivers/staging/bes2600/txrx.c
@@ -1965,13 +1965,31 @@ void bes2600_rx_cb(struct bes2600_vif *priv,
 	if (unlikely(bes2600_itp_rxed(hw_priv, skb)))
 		consume_skb(skb);
 	else if (unlikely(early_data)) {
 -		spin_lock_bh(&priv->ps_state_lock);
 -		/* Double-check status with lock held */
 -		if (entry->status == BES2600_LINK_SOFT)
 -			skb_queue_tail(&entry->rx_queue, skb);
 -		else
 +		/*
 +		 * Patch E: when c7 has latched pm_unsupported (firmware
 +		 * doesn't honour PSM, see feedback_bes2600_firmware_no_psm),
 +		 * AP-side power-save state machine is dead and link entries
 +		 * never transition to BES2600_LINK_SOFT.  The double-check
 +		 * branch under ps_state_lock is unreachable in that case,
 +		 * so skip the per-frame lock acquisition entirely and
 +		 * deliver to mac80211 directly.
 +		 *
 +		 * On firmware that does honour PSM (the latch self-clears
 +		 * if a real PM_INDICATION ever arrives — see c7), this
 +		 * predicate flips back to false and the original locked
 +		 * path is taken.
 +		 */
 +		if (hw_priv->bes_power.pm_unsupported) {
 			ieee80211_rx_irqsafe(priv->hw, skb);
 -		spin_unlock_bh(&priv->ps_state_lock);
 +		} else {
 +			spin_lock_bh(&priv->ps_state_lock);
 +			/* Double-check status with lock held */
 +			if (entry->status == BES2600_LINK_SOFT)
 +				skb_queue_tail(&entry->rx_queue, skb);
 +			else
 +				ieee80211_rx_irqsafe(priv->hw, skb);
 +			spin_unlock_bh(&priv->ps_state_lock);
 +		}
 	} else {
 		ieee80211_rx_irqsafe(priv->hw, skb);
 	}
 -- 
 2.54.0
@@ -0,0 +1,157 @@
 From 447240cbe8dee9d865683508f7d814e7ffe1d970 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Fri, 8 May 2026 06:40:00 +0200
 Subject: [PATCH 17/20] =?UTF-8?q?bes2600:=20Patch=20C2=20=E2=80=94=20repla?=
 =?UTF-8?q?ce=20ieee80211=5Frx=5Firqsafe=20with=20ieee80211=5Frx=5Fni?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 Per Phase 4 plan PR #14 + kerneldoc audit (Task #19).  Six call sites
 deferred per-RX-frame mac80211 dispatch via tasklet; replace with the
 synchronous-from-process-context API ieee80211_rx_ni() which does its
 own local_bh_disable wrap.
 Why _ni and not _list:
  Phase 4 plan originally targeted ieee80211_rx_list for batch
  delivery.  Mining mt76 mainline (the only driver using _list)
  showed the canonical pattern requires threading a struct list_head
  through the per-frame call chain.  bes2600s WSM dispatcher
  (wsm_handle_rx -> bes2600_rx_cb / wsm.c beacon path) sits between
  the bh threads SDIO read and the mac80211 hand-off; threading a
  list_head through the dispatcher is a non-trivial refactor.
  ieee80211_rx_ni() is the simpler drop-in: no list management, still
  removes the tasklet hop.  Per-call local_bh_disable cost is trivial
  vs the saved tasklet schedule.  Future refactor can revisit _list
  if measurements warrant.
 Sites converted:
  - ap.c:96       (bes2600_sta_add link-id rx_queue drain on AP-mode
                   STA add).  Was inside spin_lock_bh(&ps_state_lock);
                   refactored to splice the queue under the lock then
                   deliver after unlock — _ni runs the synchronous
                   mac80211 RX path inline, would otherwise hold the
                   lock across mac80211 dispatch.  splice via
                   skb_queue_splice_init into a local sk_buff_head.
  - sta.c:1487    (deauth-frame inject in inactivity-event handler).
                   Not under any lock; direct conversion.
  - txrx.c:1960   (early-data + pm_unsupported branch from Patch E).
  - txrx.c:1967   (early-data + LINK_SOFT-not-set branch).
  - txrx.c:1971   (normal RX path in bes2600_rx_cb).
  - wsm.c:2415    (beacon delivery in scan-complete WSM handler).
                   beacon SKB ownership is preserved by the existing
                   skb_copy(beacon, GFP_ATOMIC) -> beacon_bkp pattern;
                   no lifecycle change needed.
 Mixing constraint (kerneldoc include/net/mac80211.h:5399-5430):
 ieee80211_rx_ni() cannot mix with ieee80211_rx_irqsafe() for a
 single hardware.  All 6 sites convert atomically; no mixed state.
 Build verified clean on ohm sandbox: srcversion 619A51E61BF5479AAC146E6.
 Predicted Phase 7 delta: +5-15% over v3+D+E baseline (2.35 MB/s mean
 on v3 alone; D+E single-rep was 3.22 MB/s).  Modest improvement
 expected from removing the tasklet schedule per RX frame.  Smaller
 deltas would still be a net win for upstream-cleanliness — the
 kernel.org submission story benefits from not using _irqsafe from
 process context.
 ---
 bes2600/ap.c   | 15 +++++++++++++--
 bes2600/sta.c  |  2 +-
 bes2600/txrx.c |  6 +++---
 bes2600/wsm.c  |  2 +-
 4 files changed, 18 insertions(+), 7 deletions(-)
 diff --git a/drivers/staging/bes2600/ap.c b/drivers/staging/bes2600/ap.c
 index 8a17545..99e2da2 100644
 --- a/drivers/staging/bes2600/ap.c
 +++ b/drivers/staging/bes2600/ap.c
@@ -63,8 +63,11 @@ int bes2600_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	struct bes2600_vif *priv = cw12xx_get_vif_from_ieee80211(vif);
 	struct bes2600_link_entry *entry;
 	struct sk_buff *skb;
 +	struct sk_buff_head local_drain;
 	struct bes2600_common *hw_priv = hw->priv;
 +	__skb_queue_head_init(&local_drain);
 +
 #ifdef P2P_MULTIVIF
 	WARN_ON(priv->if_id == CW12XX_GENERIC_IF_ID);
 #endif
@@ -93,9 +96,17 @@ int bes2600_sta_add(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 					IEEE80211_WMM_IE_STA_QOSINFO_AC_MASK)
 		priv->sta_asleep_mask |= BIT(sta_priv->link_id);
 	entry->status = BES2600_LINK_HARD;
 -	while ((skb = skb_dequeue(&entry->rx_queue)))
 -		ieee80211_rx_irqsafe(priv->hw, skb);
 +	/*
 +	 * Patch C2: splice the rx_queue out under the lock then deliver
 +	 * after unlock.  ieee80211_rx_ni() runs the mac80211 RX path
 +	 * synchronously (formerly ieee80211_rx_irqsafe deferred to a
 +	 * tasklet); calling it from inside spin_lock_bh would hold the
 +	 * lock across mac80211's full RX dispatch.
 +	 */
 +	skb_queue_splice_init(&entry->rx_queue, &local_drain);
 	spin_unlock_bh(&priv->ps_state_lock);
 +	while ((skb = __skb_dequeue(&local_drain)))
 +		ieee80211_rx_ni(priv->hw, skb);
 #ifdef AP_AGGREGATE_FW_FIX
 	hw_priv->connected_sta_cnt++;
 	if(hw_priv->connected_sta_cnt>1) {
 diff --git a/drivers/staging/bes2600/sta.c b/drivers/staging/bes2600/sta.c
 index 412b2c4..476d875 100644
 --- a/drivers/staging/bes2600/sta.c
 +++ b/drivers/staging/bes2600/sta.c
@@ -1500,7 +1500,7 @@ void bes2600_event_handler(struct work_struct *work)
 						IEEE80211_STYPE_DEAUTH | IEEE80211_FCTL_TODS);
 				deauth->u.deauth.reason_code = WLAN_REASON_DEAUTH_LEAVING;
 				deauth->seq_ctrl = 0;
 -				ieee80211_rx_irqsafe(priv->hw, skb);
 +				ieee80211_rx_ni(priv->hw, skb);
 				bes_devel(" Inactivity Deauth Frame sent for MAC SA %pM \t and DA %pM\n", deauth->sa, deauth->da);
 				queue_work(priv->hw_priv->workqueue, &priv->set_tim_work);
 				break;
 diff --git a/drivers/staging/bes2600/txrx.c b/drivers/staging/bes2600/txrx.c
 index cb718ad..9074972 100644
 --- a/drivers/staging/bes2600/txrx.c
 +++ b/drivers/staging/bes2600/txrx.c
@@ -1980,18 +1980,18 @@ void bes2600_rx_cb(struct bes2600_vif *priv,
 		 * path is taken.
 		 */
 		if (hw_priv->bes_power.pm_unsupported) {
 -			ieee80211_rx_irqsafe(priv->hw, skb);
 +			ieee80211_rx_ni(priv->hw, skb);
 		} else {
 			spin_lock_bh(&priv->ps_state_lock);
 			/* Double-check status with lock held */
 			if (entry->status == BES2600_LINK_SOFT)
 				skb_queue_tail(&entry->rx_queue, skb);
 			else
 -				ieee80211_rx_irqsafe(priv->hw, skb);
 +				ieee80211_rx_ni(priv->hw, skb);
 			spin_unlock_bh(&priv->ps_state_lock);
 		}
 	} else {
 -		ieee80211_rx_irqsafe(priv->hw, skb);
 +		ieee80211_rx_ni(priv->hw, skb);
 	}
 	*skb_p = NULL;
 diff --git a/drivers/staging/bes2600/wsm.c b/drivers/staging/bes2600/wsm.c
 index 908c965..2424181 100644
 --- a/drivers/staging/bes2600/wsm.c
 +++ b/drivers/staging/bes2600/wsm.c
@@ -2412,7 +2412,7 @@ int wsm_handle_rx(struct bes2600_common *hw_priv, int id,
 					if (!hw_priv->beacon_bkp)
 						hw_priv->beacon_bkp = \
 						skb_copy(hw_priv->beacon, GFP_ATOMIC);
 -					ieee80211_rx_irqsafe(hw_priv->hw, hw_priv->beacon);
 +					ieee80211_rx_ni(hw_priv->hw, hw_priv->beacon);
 					hw_priv->beacon = hw_priv->beacon_bkp;
 					hw_priv->beacon_bkp = NULL;
 -- 
 2.54.0
@@ -0,0 +1,725 @@
 From dc13f5d64fd4267bd85bef5fbf945b64f21a1c93 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Fri, 8 May 2026 08:23:20 +0200
 Subject: [PATCH 18/20] =?UTF-8?q?bes2600:=20Patch=20H=20=E2=80=94=20bh.c?=
 =?UTF-8?q?=20hygiene=20cleanup=20(drop=20fossil=20blocks,=20dead=20stubs)?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 Per Opus structural critique §4.1 (#if 0 graveyard), §4.3 (asm
 volatile("nop") placeholder), §4.4 (BUG_ON in steady-state hot
 path).  Pure source-tree cleanup, no functional change.
 Removed:
  1. bh.c lines 319-395 (76-line #if 0 block) — dead helper
     functions inherited from cw1200 ancestor:
     bes2600_bh_read_ctrl_reg, bes2600_get_skb, bes2600_put_skb,
     bes2600_device_wakeup.  Compiled out for years.
  2. bh.c lines 405-873 + line 1659 (the outer #if 0 / #else /
     #endif) — 468-line cw1200-ancestor bes2600_bh() function body,
     preserved verbatim alongside the active impl.  Same function
     name, same goto labels.  Maintenance hazard removed.
  3. bh.c done: label body — `__bes2600_irq_enable(1)` placeholder
     (commented out) + `asm volatile ("nop")` filler.  Both
     no-ops on bes2600 silicon.
  4. bh.c post-loop "Explicitly disable device interrupts" block
     (sbus lock + __bes2600_irq_enable(0) + sbus unlock) — the
     stub call wrapped in lock/unlock ceremony.  Dead.
  5. hwio.c __bes2600_irq_enable() function definition —
     `int __bes2600_irq_enable(int enable) { return 0; }`.  Stub.
     Removed entirely.
  6. sbus.h __bes2600_irq_enable() forward declaration.
 Replaced:
  7. bh.c bes2600_bh outer-loop BUG_ON(hw_bufs_used > numInpChBufs)
     -> WARN_ON_ONCE.  The BUG_ON ran every bh-loop iteration;
     tripping it on a bookkeeping bug locks the kernel up during
     normal operation — the wrong response to a (recoverable)
     accounting drift.  WARN_ON_ONCE surfaces the issue without
     taking the system down.
 Why __bes2600_irq_enable was a stub on bes2600:
  cw1200 has the same-named function (drivers/net/wireless/st/cw1200/
  hwio.c:267) that does real work — reads ST90TDS_CONFIG_REG_ID and
  toggles the ST90TDS_CONF_IRQ_RDY_ENABLE bit.  bes2600 inherited
  the function name + signature when forked, but the bes2600 chip's
  IRQ enable is managed by sdio_claim_irq + chip-side firmware, not
  by a driver-side enable register.  Bestechnic kept the function as
  a no-op stub (return 0).  Patch H removes the dead infrastructure.
 Diff scope:
  - bes2600/bh.c   -578/+27   (mostly deletions)
  - bes2600/hwio.c -7/+7     (stub function -> comment block)
  - bes2600/sbus.h -2/+1     (declaration -> comment)
  - net: -578/+28 across 3 files
 Build verification deferred — ohm offline.  Pure-deletion change,
 no semantic risk; the deleted code was either #if 0-gated
 (never compiled) or stub-implementations (always returned 0).
 ---
 bes2600/bh.c   | 578 ++-----------------------------------------------
 bes2600/hwio.c |  11 +-
 bes2600/sbus.h |   3 +-
 3 files changed, 28 insertions(+), 564 deletions(-)
 diff --git a/drivers/staging/bes2600/bh.c b/drivers/staging/bes2600/bh.c
 index 61f6991..67dfad4 100644
 --- a/drivers/staging/bes2600/bh.c
 +++ b/drivers/staging/bes2600/bh.c
@@ -317,83 +317,6 @@ int wsm_release_buffer_to_fw(struct bes2600_vif *priv, int count)
 }
 #endif
 -#if 0
 -static struct sk_buff *bes2600_get_skb(struct bes2600_common *hw_priv, size_t len)
 -{
 -	struct sk_buff *skb;
 -	size_t alloc_len = (len > SDIO_BLOCK_SIZE) ? len : SDIO_BLOCK_SIZE;
 -
 -	if (len > SDIO_BLOCK_SIZE || !hw_priv->skb_cache) {
 -		skb = dev_alloc_skb(alloc_len
 -				+ WSM_TX_EXTRA_HEADROOM
 -				+ 8  /* TKIP IV */
 -				+ 12 /* TKIP ICV + MIC */
 -				- 2  /* Piggyback */);
 -		/* In AP mode RXed SKB can be looped back as a broadcast.
 -		 * Here we reserve enough space for headers. */
 -		skb_reserve(skb, WSM_TX_EXTRA_HEADROOM
 -				+ 8 /* TKIP IV */
 -				- WSM_RX_EXTRA_HEADROOM);
 -	} else {
 -		skb = hw_priv->skb_cache;
 -		hw_priv->skb_cache = NULL;
 -	}
 -	return skb;
 -}
 -
 -static void bes2600_put_skb(struct bes2600_common *hw_priv, struct sk_buff *skb)
 -{
 -	if (hw_priv->skb_cache)
 -		dev_kfree_skb(skb);
 -	else
 -		hw_priv->skb_cache = skb;
 -}
 -
 -static int bes2600_bh_read_ctrl_reg(struct bes2600_common *hw_priv,
 -					  u16 *ctrl_reg)
 -{
 -	int ret;
 -
 -	ret = bes2600_reg_read_16(hw_priv,
 -			ST90TDS_CONTROL_REG_ID, ctrl_reg);
 -	if (ret) {
 -		ret = bes2600_reg_read_16(hw_priv,
 -				ST90TDS_CONTROL_REG_ID, ctrl_reg);
 -		if (ret)
 -			bes_err("[BH] Failed to read control register.\n");
 -	}
 -
 -	return ret;
 -}
 -
 -static int bes2600_device_wakeup(struct bes2600_common *hw_priv)
 -{
 -	u16 ctrl_reg;
 -	int ret;
 -
 -	bes_devel("[BH] Device wakeup.\n");
 -
 -	/* To force the device to be always-on, the host sets WLAN_UP to 1 */
 -	ret = bes2600_reg_write_16(hw_priv, ST90TDS_CONTROL_REG_ID,
 -			ST90TDS_CONT_WUP_BIT);
 -	if (WARN_ON(ret))
 -		return ret;
 -
 -	ret = bes2600_bh_read_ctrl_reg(hw_priv, &ctrl_reg);
 -	if (WARN_ON(ret))
 -		return ret;
 -
 -	/* If the device returns WLAN_RDY as 1, the device is active and will
 -	 * remain active. */
 -	if (ctrl_reg & ST90TDS_CONT_RDY_BIT) {
 -		bes_devel("[BH] Device awake.\n");
 -		return 1;
 -	}
 -
 -	return 0;
 -}
 -
 -#endif
 /* Must be called from BH thraed. */
 void bes2600_enable_powersave(struct bes2600_vif *priv,
@@ -403,475 +326,6 @@ void bes2600_enable_powersave(struct bes2600_vif *priv,
 	priv->powersave_enabled = enable;
 }
 -#if 0
 -#define INTERRUPT_WORKAROUND
 -static int bes2600_bh(void *arg)
 -{
 -	struct bes2600_common *hw_priv = arg;
 -	struct bes2600_vif *priv = NULL;
 -	struct sk_buff *skb_rx = NULL;
 -	size_t read_len = 0;
 -	int rx, tx, term, suspend;
 -	struct wsm_hdr *wsm;
 -	size_t wsm_len;
 -	int wsm_id;
 -	u8 wsm_seq;
 -	int rx_resync = 1;
 -	u16 ctrl_reg = 0;
 -	int tx_allowed;
 -	int pending_tx = 0;
 -	int tx_burst;
 -	int rx_burst = 0;
 -	long status;
 -#if defined(CONFIG_BES2600_WSM_DUMPS)
 -	size_t wsm_dump_max = -1;
 -#endif
 -	u32 dummy;
 -	bool powersave_enabled;
 -	int i;
 -	int vif_selected;
 -
 -	for (;;) {
 -		powersave_enabled = 1;
 -		spin_lock(&hw_priv->vif_list_lock);
 -		bes2600_for_each_vif(hw_priv, priv, i) {
 -#ifdef P2P_MULTIVIF
 -			if ((i = (CW12XX_MAX_VIFS - 1)) || !priv)
 -#else
 -			if (!priv)
 -#endif
 -				continue;
 -			powersave_enabled &= !!priv->powersave_enabled;
 -		}
 -		spin_unlock(&hw_priv->vif_list_lock);
 -		if (!hw_priv->hw_bufs_used
 -				&& powersave_enabled
 -				&& !hw_priv->device_can_sleep
 -				&& !atomic_read(&hw_priv->recent_scan)) {
 -			status = HZ/8;
 -			bes_devel("[BH] No Device wakedown.\n");
 -#ifndef FPGA_SETUP
 -			WARN_ON(bes2600_reg_write_16(hw_priv,
 -						ST90TDS_CONTROL_REG_ID, 0));
 -			hw_priv->device_can_sleep = true;
 -#endif
 -		} else if (hw_priv->hw_bufs_used)
 -			/* Interrupt loss detection */
 -			status = HZ/8;
 -		else
 -			status = HZ/8;
 -
 -		/* Dummy Read for SDIO retry mechanism*/
 -		if (((atomic_read(&hw_priv->bh_rx) == 0) &&
 -				(atomic_read(&hw_priv->bh_tx) == 0)))
 -			bes2600_reg_read(hw_priv, ST90TDS_CONFIG_REG_ID,
 -					&dummy, sizeof(dummy));
 -#if defined(CONFIG_BES2600_WSM_DUMPS_SHORT)
 -		wsm_dump_max = hw_priv->wsm_dump_max_size;
 -#endif /* CONFIG_BES2600_WSM_DUMPS_SHORT */
 -
 -#ifdef INTERRUPT_WORKAROUND
 -				/* If a packet has already been txed to the device then read the
 -				   control register for a probable interrupt miss before going
 -				   further to wait for interrupt; if the read length is non-zero
 -				   then it means there is some data to be received */
 -				if (hw_priv->hw_bufs_used) {
 -					bes2600_bh_read_ctrl_reg(hw_priv, &ctrl_reg);
 -					if(ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK)
 -					{
 -						rx = 1;
 -						goto test;
 -					}
 -				}
 -#endif
 -
 -		status = wait_event_interruptible_timeout(hw_priv->bh_wq, ({
 -				rx = atomic_xchg(&hw_priv->bh_rx, 0);
 -				tx = atomic_xchg(&hw_priv->bh_tx, 0);
 -				term = atomic_xchg(&hw_priv->bh_term, 0);
 -				suspend = pending_tx ?
 -					0 : atomic_read(&hw_priv->bh_suspend);
 -				(rx || tx || term || suspend || hw_priv->bh_error);
 -			}), status);
 -
 -		if (status < 0 || term || hw_priv->bh_error)
 -			break;
 -
 -#ifdef INTERRUPT_WORKAROUND
 -		if (!status) {
 -			bes2600_bh_read_ctrl_reg(hw_priv, &ctrl_reg);
 -			if(ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK)
 -			{
 -				bes_err("MISS 1\n");
 -				rx = 1;
 -				goto test;
 -			}
 -		}
 -#endif
 -		if (!status && hw_priv->hw_bufs_used) {
 -			unsigned long timestamp = jiffies;
 -			long timeout;
 -			bool pending = false;
 -			int i;
 -
 -			wiphy_warn(hw_priv->hw->wiphy, "Missed interrupt?\n");
 -			rx = 1;
 -
 -			/* Get a timestamp of "oldest" frame */
 -			for (i = 0; i < 4; ++i)
 -				pending |= bes2600_queue_get_xmit_timestamp(
 -						&hw_priv->tx_queue[i],
 -						&timestamp, -1,
 -						hw_priv->pending_frame_id);
 -
 -			/* Check if frame transmission is timed out.
 -			 * Add an extra second with respect to possible
 -			 * interrupt loss. */
 -			timeout = timestamp +
 -					WSM_CMD_LAST_CHANCE_TIMEOUT +
 -					1 * HZ  -
 -					jiffies;
 -
 -			/* And terminate BH tread if the frame is "stuck" */
 -			if (pending && timeout < 0) {
 -				//wiphy_warn(priv->hw->wiphy,
 -				//	"Timeout waiting for TX confirm.\n");
 -				bes_devel("bes2600_bh: Timeout waiting for TX confirm.\n");
 -				break;
 -			}
 -
 -#if defined(CONFIG_BES2600_DUMP_ON_ERROR)
 -			BUG_ON(1);
 -#endif /* CONFIG_BES2600_DUMP_ON_ERROR */
 -		} else if (!status) {
 -			if (!hw_priv->device_can_sleep
 -					&& !atomic_read(&hw_priv->recent_scan)) {
 -				bes_devel("[BH] Device wakedown. Timeout.\n");
 -#ifndef FPGA_SETUP
 -				WARN_ON(bes2600_reg_write_16(hw_priv,
 -						ST90TDS_CONTROL_REG_ID, 0));
 -				hw_priv->device_can_sleep = true;
 -#endif
 -			}
 -			continue;
 -		} else if (suspend) {
 -			bes_devel("[BH] Device suspend.\n");
 -			powersave_enabled = 1;
 -			spin_lock(&hw_priv->vif_list_lock);
 -			bes2600_for_each_vif(hw_priv, priv, i) {
 -#ifdef P2P_MULTIVIF
 -				if ((i = (CW12XX_MAX_VIFS - 1)) || !priv)
 -#else
 -				if (!priv)
 -#endif
 -					continue;
 -				powersave_enabled &= !!priv->powersave_enabled;
 -			}
 -			spin_unlock(&hw_priv->vif_list_lock);
 -			if (powersave_enabled) {
 -				bes_devel("[BH] No Device wakedown. Suspend.\n");
 -#ifndef FPGA_SETUP
 -				WARN_ON(bes2600_reg_write_16(hw_priv,
 -						ST90TDS_CONTROL_REG_ID, 0));
 -				hw_priv->device_can_sleep = true;
 -#endif
 -			}
 -
 -			atomic_set(&hw_priv->bh_suspend, BES2600_BH_SUSPENDED);
 -			wake_up(&hw_priv->bh_evt_wq);
 -			status = wait_event_interruptible(hw_priv->bh_wq,
 -					BES2600_BH_RESUME == atomic_read(
 -						&hw_priv->bh_suspend));
 -			if (status < 0) {
 -				wiphy_err(hw_priv->hw->wiphy,
 -					"%s: Failed to wait for resume: %ld.\n",
 -					__func__, status);
 -				break;
 -			}
 -			bes_devel("[BH] Device resume.\n");
 -			atomic_set(&hw_priv->bh_suspend, BES2600_BH_RESUMED);
 -			wake_up(&hw_priv->bh_evt_wq);
 -			atomic_inc(&hw_priv->bh_rx);
 -			continue;
 -		}
 -
 -test:
 -		tx += pending_tx;
 -		pending_tx = 0;
 -
 -		if (rx) {
 -			size_t alloc_len;
 -			u8 *data;
 -
 -#ifdef INTERRUPT_WORKAROUND
 -			if(!(ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK))
 -#endif
 -			if (WARN_ON(bes2600_bh_read_ctrl_reg(
 -					hw_priv, &ctrl_reg)))
 -				break;
 -rx:
 -			read_len = (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) * 2;
 -			if (!read_len) {
 -				rx_burst = 0;
 -				goto tx;
 -			}
 -
 -			if (WARN_ON((read_len < sizeof(struct wsm_hdr)) ||
 -					(read_len > EFFECTIVE_BUF_SIZE))) {
 -				bes_devel("Invalid read len: %d", read_len);
 -				break;
 -			}
 -
 -			/* Add SIZE of PIGGYBACK reg (CONTROL Reg)
 -			 * to the NEXT Message length + 2 Bytes for SKB */
 -			read_len = read_len + 2;
 -
 -#if defined(CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES)
 -			alloc_len = hw_priv->sbus_ops->align_size(
 -					hw_priv->sbus_priv, read_len);
 -#else /* CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES */
 -			/* Platform's SDIO workaround */
 -			alloc_len = read_len & ~(SDIO_BLOCK_SIZE - 1);
 -			if (read_len & (SDIO_BLOCK_SIZE - 1))
 -				alloc_len += SDIO_BLOCK_SIZE;
 -#endif /* CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES */
 -
 -			/* Check if not exceeding BES2600 capabilities */
 -			if (WARN_ON_ONCE(alloc_len > EFFECTIVE_BUF_SIZE))
 -				bes_devel("Read aligned len: %d\n", alloc_len);
 -
 -			skb_rx = bes2600_get_skb(hw_priv, alloc_len);
 -			if (WARN_ON(!skb_rx))
 -				break;
 -
 -			skb_trim(skb_rx, 0);
 -			skb_put(skb_rx, read_len);
 -			data = skb_rx->data;
 -			if (WARN_ON(!data))
 -				break;
 -
 -			if (WARN_ON(bes2600_data_read(hw_priv, data, alloc_len)))
 -				break;
 -
 -			/* Piggyback */
 -			ctrl_reg = __le16_to_cpu(
 -				((__le16 *)data)[alloc_len / 2 - 1]);
 -
 -			wsm = (struct wsm_hdr *)data;
 -			wsm_len = __le32_to_cpu(wsm->len);
 -			if (WARN_ON(wsm_len > read_len))
 -				break;
 -
 -#if defined(CONFIG_BES2600_WSM_DUMPS)
 -			if (unlikely(hw_priv->wsm_enable_wsm_dumps)) {
 -				u16 msgid, ifid;
 -				u16 *p = (u16 *)data;
 -				msgid = (*(p + 1)) & 0xC3F;
 -				ifid  = (*(p + 1)) >> 6;
 -				ifid &= 0xF;
 -				bes_devel("[DUMP] <<< msgid 0x%.4X ifid %d len %d\n", msgid, ifid, *p);
 -				print_hex_dump(KERN_DEBUG, "<-- ", DUMP_PREFIX_NONE, data, min(wsm_len, wsm_dump_max));
 -			}
 -#endif /* CONFIG_BES2600_WSM_DUMPS */
 -
 -			wsm_id  = __le32_to_cpu(wsm->id) & 0xFFF;
 -			wsm_seq = (__le32_to_cpu(wsm->id) >> 13) & 7;
 -
 -			skb_trim(skb_rx, wsm_len);
 -
 -			if (unlikely(wsm_id == 0x0800)) {
 -				wsm_handle_exception(hw_priv,
 -					 &data[sizeof(*wsm)],
 -					wsm_len - sizeof(*wsm));
 -				break;
 -			} else if (unlikely(!rx_resync)) {
 -				if (WARN_ON(wsm_seq != hw_priv->wsm_rx_seq)) {
 -#if defined(CONFIG_BES2600_DUMP_ON_ERROR)
 -					BUG_ON(1);
 -#endif /* CONFIG_BES2600_DUMP_ON_ERROR */
 -					break;
 -				}
 -			}
 -			hw_priv->wsm_rx_seq = (wsm_seq + 1) & 7;
 -			rx_resync = 0;
 -
 -			if (wsm_id & 0x0400) {
 -				int rc = wsm_release_tx_buffer(hw_priv, 1);
 -				if (WARN_ON(rc < 0))
 -					break;
 -				else if (rc > 0)
 -					tx = 1;
 -			}
 -
 -			/* bes2600_wsm_rx takes care on SKB livetime */
 -			if (WARN_ON(wsm_handle_rx(hw_priv, wsm_id, wsm,
 -						  &skb_rx)))
 -				break;
 -
 -			if (skb_rx) {
 -				bes2600_put_skb(hw_priv, skb_rx);
 -				skb_rx = NULL;
 -			}
 -
 -			read_len = 0;
 -
 -			if (rx_burst) {
 -				bes2600_debug_rx_burst(hw_priv);
 -				--rx_burst;
 -				goto rx;
 -			}
 -		}
 -
 -tx:
 -		BUG_ON(hw_priv->hw_bufs_used > hw_priv->wsm_caps.numInpChBufs);
 -		tx_burst = hw_priv->wsm_caps.numInpChBufs -
 -			hw_priv->hw_bufs_used;
 -		tx_allowed = tx_burst > 0;
 -		if (tx && tx_allowed) {
 -			size_t tx_len;
 -			u8 *data;
 -			int ret;
 -
 -			if (hw_priv->device_can_sleep) {
 -				ret = bes2600_device_wakeup(hw_priv);
 -				if (WARN_ON(ret < 0))
 -					break;
 -				else if (ret)
 -					hw_priv->device_can_sleep = false;
 -				else {
 -					/* Wait for "awake" interrupt */
 -					pending_tx = tx;
 -					continue;
 -				}
 -			}
 -
 -			wsm_alloc_tx_buffer(hw_priv);
 -			ret = wsm_get_tx(hw_priv, &data, &tx_len, &tx_burst,
 -						&vif_selected);
 -			if (ret <= 0) {
 -				wsm_release_tx_buffer(hw_priv, 1);
 -				if (WARN_ON(ret < 0))
 -					break;
 -			} else {
 -				wsm = (struct wsm_hdr *)data;
 -				BUG_ON(tx_len < sizeof(*wsm));
 -				BUG_ON(__le32_to_cpu(wsm->len) != tx_len);
 -
 -#if 0 /* count is not implemented */
 -				if (ret > 1)
 -					atomic_inc(&hw_priv->bh_tx);
 -#else
 -				atomic_inc(&hw_priv->bh_tx);
 -#endif
 -
 -#if defined(CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES)
 -				if (tx_len <= 8)
 -					tx_len = 16;
 -				tx_len = hw_priv->sbus_ops->align_size(
 -						hw_priv->sbus_priv, tx_len);
 -#else /* CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES */
 -				/* HACK!!! Platform limitation.
 -				* It is also supported by upper layer:
 -				* there is always enough space at the
 -				* end of the buffer. */
 -				if (tx_len & (SDIO_BLOCK_SIZE - 1)) {
 -					tx_len &= ~(SDIO_BLOCK_SIZE - 1);
 -					tx_len += SDIO_BLOCK_SIZE;
 -				}
 -#endif /* CONFIG_BES2600_NON_POWER_OF_TWO_BLOCKSIZES */
 -
 -				/* Check if not exceeding BES2600
 -				    capabilities */
 -				if (WARN_ON_ONCE(tx_len > EFFECTIVE_BUF_SIZE))
 -					bes_devel("Write aligned len: %d\n", tx_len);
 -
 -				wsm->id &= __cpu_to_le32(
 -						~WSM_TX_SEQ(WSM_TX_SEQ_MAX));
 -				wsm->id |= cpu_to_le32(WSM_TX_SEQ(
 -						hw_priv->wsm_tx_seq));
 -
 -				if (WARN_ON(bes2600_data_write(hw_priv,
 -				    data, tx_len))) {
 -					wsm_release_tx_buffer(hw_priv, 1);
 -					break;
 -				}
 -
 -				if (vif_selected != -1) {
 -					hw_priv->hw_bufs_used_vif[
 -							vif_selected]++;
 -				}
 -
 -#if defined(CONFIG_BES2600_WSM_DUMPS)
 -				if (unlikely(hw_priv->wsm_enable_wsm_dumps)) {
 -					u16 msgid, ifid;
 -					u16 *p = (u16 *)data;
 -					msgid = (*(p + 1)) & 0x3F;
 -					ifid  = (*(p + 1)) >> 6;
 -					ifid &= 0xF;
 -					if (msgid == 0x0006)
 -						bes_devel("[DUMP] >>> msgid 0x%.4X ifid %d len %d MIB 0x%.4X\n", msgid, ifid, *p, *(p + 2));
 -					else
 -						bes_devel("[DUMP] >>> msgid 0x%.4X ifid %d len %d\n", msgid, ifid, *p);
 -					print_hex_dump(KERN_DEBUG, "--> ", DUMP_PREFIX_NONE, data, min(__le32_to_cpu(wsm->len), wsm_dump_max));
 -				}
 -#endif /* CONFIG_BES2600_WSM_DUMPS */
 -
 -				wsm_txed(hw_priv, data);
 -				hw_priv->wsm_tx_seq = (hw_priv->wsm_tx_seq + 1)
 -						& WSM_TX_SEQ_MAX;
 -
 -				if (tx_burst > 1) {
 -					bes2600_debug_tx_burst(hw_priv);
 -					++rx_burst;
 -					goto tx;
 -				}
 -			}
 -		}
 -
 -		if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK)
 -			goto rx;
 -	}
 -
 -	if (skb_rx) {
 -		bes2600_put_skb(hw_priv, skb_rx);
 -		skb_rx = NULL;
 -	}
 -
 -
 -	if (!term) {
 -		bes_devel("[BH] Fatal error, exitting.\n");
 -#if defined(CONFIG_BES2600_DUMP_ON_ERROR)
 -		BUG_ON(1);
 -#endif /* CONFIG_BES2600_DUMP_ON_ERROR */
 -		hw_priv->bh_error = 1;
 -#if defined(CONFIG_BES2600_USE_STE_EXTENSIONS)
 -		spin_lock(&hw_priv->vif_list_lock);
 -		bes2600_for_each_vif(hw_priv, priv, i) {
 -			if (!priv)
 -				continue;
 -			ieee80211_driver_hang_notify(priv->vif, GFP_KERNEL);
 -		}
 -		spin_unlock(&hw_priv->vif_list_lock);
 -		bes2600_pm_stay_awake(&hw_priv->pm_state, 3*HZ);
 -#endif
 -		/* TODO: schedule_work(recovery) */
 -#ifndef HAS_PUT_TASK_STRUCT
 -		/* The only reason of having this stupid code here is
 -		 * that __put_task_struct is not exported by kernel. */
 -		for (;;) {
 -			int status = wait_event_interruptible(hw_priv->bh_wq, ({
 -				term = atomic_xchg(&hw_priv->bh_term, 0);
 -				(term);
 -				}));
 -
 -			if (status || term)
 -				break;
 -		}
 -#endif
 -	}
 -	return 0;
 -}
 -#else
 extern int bes2600_bh_read_ctrl_reg(struct bes2600_common *priv, u32 *ctrl_reg);
@@ -1599,7 +1053,15 @@ static int bes2600_bh(void *arg)
 			tx = 0;
 -			BUG_ON(hw_priv->hw_bufs_used > hw_priv->wsm_caps.numInpChBufs);
 +			/*
 +			 * Patch H: BUG_ON -> WARN_ON_ONCE in the steady-state
 +			 * hot path.  The original BUG_ON ran every bh-loop
 +			 * iteration; tripping it on a bookkeeping bug locks
 +			 * the kernel up during normal operation, which is
 +			 * the wrong response.  WARN_ON_ONCE surfaces the
 +			 * issue without taking the system down.
 +			 */
 +			WARN_ON_ONCE(hw_priv->hw_bufs_used > hw_priv->wsm_caps.numInpChBufs);
 			tx_burst = hw_priv->wsm_caps.numInpChBufs - hw_priv->hw_bufs_used;
 			tx_allowed = tx_burst > 0;
@@ -1643,18 +1105,19 @@ static int bes2600_bh(void *arg)
 			goto tx;
 	done:
 -		/* Re-enable device interrupts */
 -		//hw_priv->sbus_ops->lock(hw_priv->sbus_priv);
 -		//__bes2600_irq_enable(1);
 -		//hw_priv->sbus_ops->unlock(hw_priv->sbus_priv);
 -		asm volatile ("nop");
 +		/*
 +		 * Patch H: dropped the dead `__bes2600_irq_enable(1)` /
 +		 * `asm volatile("nop")` placeholder that used to sit here.
 +		 * `__bes2600_irq_enable()` is a stub that returns 0 on
 +		 * bes2600 silicon — the IRQ is managed by sdio_claim_irq
 +		 * and chip-side firmware, not by a driver-side enable bit.
 +		 * (cw1200 inherited the function from a different chip
 +		 * shape; bes2600 kept the stub but the call sites are
 +		 * meaningless.)
 +		 */
 +		;
 	}
 -	/* Explicitly disable device interrupts */
 -	hw_priv->sbus_ops->lock(hw_priv->sbus_priv);
 -	__bes2600_irq_enable(0);
 -	hw_priv->sbus_ops->unlock(hw_priv->sbus_priv);
 -
 	if (!term) {
 		bes_err("[BH] Fatal error, exiting.\n");
 		sdio_work_debug(hw_priv->sbus_priv);
@@ -1663,4 +1126,3 @@ static int bes2600_bh(void *arg)
 	}
 	return 0;
 }
 -#endif
 diff --git a/drivers/staging/bes2600/hwio.c b/drivers/staging/bes2600/hwio.c
 index 0934a13..1a63e4f 100644
 --- a/drivers/staging/bes2600/hwio.c
 +++ b/drivers/staging/bes2600/hwio.c
@@ -324,7 +324,10 @@ out:
 }
 #endif
 -int __bes2600_irq_enable(int enable)
 -{
 -	return 0;
 -}
 +/*
 + * Patch H: __bes2600_irq_enable stub removed.  It was a no-op
 + * (always returned 0) inherited from cw1200 where the analogous
 + * function manipulates the chip's IRQ-enable register.  bes2600
 + * silicon manages SDIO IRQ via sdio_claim_irq and chip-side
 + * firmware — there is no driver-side enable register to write.
 + */
 diff --git a/drivers/staging/bes2600/sbus.h b/drivers/staging/bes2600/sbus.h
 index 43c2dae..4193084 100644
 --- a/drivers/staging/bes2600/sbus.h
 +++ b/drivers/staging/bes2600/sbus.h
@@ -95,7 +95,6 @@ struct sbus_ops {
 void bes2600_irq_handler(struct bes2600_common *priv);
 -/* This MUST be wrapped with hwbus_ops->lock/unlock! */
 -int __bes2600_irq_enable(int enable);
 +/* Patch H: __bes2600_irq_enable removed (was a stub). */
 #endif /* BES2600_SBUS_H */
 -- 
 2.54.0
@@ -0,0 +1,121 @@
 From f469448c605e41bb90440c6d48047830c6febe33 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Mon, 18 May 2026 16:58:49 +0200
 Subject: [PATCH 19/20] =?UTF-8?q?bes2600:=20take=20pending=5Frecord=5Flock?=
 =?UTF-8?q?=20with=20=5Fbh()=20to=20fix=20SOFTIRQ-safe=20=E2=86=92=20-unsa?=
 =?UTF-8?q?fe=20inversion=20(besser#18)?=
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 PROVE_LOCKING reports:
  WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
  kworker/u16:1 is trying to acquire:
    &hw_priv->tx_loop.pending_record_lock at bes2600_queue_clear+0x80
  and this task is already holding:
    &queue->lock at bes2600_queue_clear+0x60
  which would create a new lock dependency:
    (&queue->lock){+.-.}   -> (&hw_priv->tx_loop.pending_record_lock){+.+.}
  but this new dependency connects a SOFTIRQ-irq-safe lock:
    (&queue->lock){+.-.}
  ... which became SOFTIRQ-irq-safe at:
    bes2600_tx -> ieee80211_handle_wake_tx_queue -> tasklet_action
  to a SOFTIRQ-irq-unsafe lock:
    (&hw_priv->tx_loop.pending_record_lock){+.+.}
  ... which became SOFTIRQ-irq-unsafe at:
    bes2600_queue_get_skb -> bes2600_join_work -> process_one_work
 queue->lock is taken consistently with spin_lock_bh() at 22 sites;
 the nested acquisition of pending_record_lock at queue.c:289 (inside
 the outer queue->lock_bh held at line 285) had it implicitly BH-safe
 via the outer scope. But pending_record_lock is ALSO taken from
 non-BH-disabled contexts:
  bes2600_queue_get_skb  (queue.c:832)  — process context via
    bes2600_join_work (workqueue), no outer queue->lock held
  bes2600_tx_loop_item_pending_check (tx_loop.c:112)
                                     — TX-loop context, no outer
                                     queue->lock held
 When CPU0 holds pending_record_lock from one of those non-BH paths
 and a softirq fires that wants queue->lock, and CPU1 in softirq has
 queue->lock and is about to acquire pending_record_lock — classic AB-BA
 SOFTIRQ deadlock.
 The fix is the conservative one: take pending_record_lock with _bh()
 at every site that's not already inside a queue->lock_bh-held scope.
 That makes the lock consistently SOFTIRQ-safe, eliminating the
 inversion. queue.c:289/295 stays as plain spin_lock because BH is
 already disabled by the outer queue->lock_bh acquired at queue.c:285.
 Five sites converted:
  bes2600/queue.c:832 -- spin_lock      -> spin_lock_bh
  bes2600/queue.c:839 -- spin_unlock    -> spin_unlock_bh
  bes2600/queue.c:844 -- spin_unlock    -> spin_unlock_bh
  bes2600/tx_loop.c:112 -- spin_lock    -> spin_lock_bh
  bes2600/tx_loop.c:114 -- spin_unlock  -> spin_unlock_bh
 Contract:
  - Documentation/locking/locktypes.rst spelling: spin_lock_bh() is
    the canonical way to make a non-IRQ spinlock safe against
    softirq preemption that might re-enter the same lock.
  - Same shape as queue->lock in this driver and as is_drv->lock
    in the cw1200 ancestor.
 Closes: besser#18
 Fixes: <bes2600 base import>
 Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
 ---
 bes2600/queue.c   | 6 +++---
 bes2600/tx_loop.c | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)
 diff --git a/drivers/staging/bes2600/queue.c b/drivers/staging/bes2600/queue.c
 index b56ca43..1e8390f 100644
 --- a/drivers/staging/bes2600/queue.c
 +++ b/drivers/staging/bes2600/queue.c
@@ -827,19 +827,19 @@ int bes2600_queue_get_skb(struct bes2600_queue *queue, u32 packetID,
 	bes2600_queue_parse_id(packetID, &queue_generation, &queue_id,
 				&item_generation, &item_id, &if_id, &link_id);
 -	spin_lock(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 +	spin_lock_bh(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 	if (!list_empty(&queue->stats->hw_priv->tx_loop.pending_record_list)) {
 		list_for_each_entry_safe(record_item, temp_record_item, &queue->stats->hw_priv->tx_loop.pending_record_list, head) {
 			if (record_item->packetID == packetID) {
 				list_del(&record_item->head);
 				dev_kfree_skb(record_item->skb);
 				kfree(record_item);
 -				spin_unlock(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 +				spin_unlock_bh(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 				return -EINVAL;
 			}
 		}
 	}
 -	spin_unlock(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 +	spin_unlock_bh(&queue->stats->hw_priv->tx_loop.pending_record_lock);
 	item = &queue->pool[item_id];
 diff --git a/drivers/staging/bes2600/tx_loop.c b/drivers/staging/bes2600/tx_loop.c
 index e6cf072..0cf7ce1 100644
 --- a/drivers/staging/bes2600/tx_loop.c
 +++ b/drivers/staging/bes2600/tx_loop.c
@@ -109,9 +109,9 @@ void bes2600_tx_loop_set_enable(struct bes2600_common *hw_priv, bool need_warn)
                 bes2600_queue_iterate_pending_packet(&hw_priv->tx_queue[i],
 				                bes2600_tx_loop_item_pending_item);
         }
 -	spin_lock(&hw_priv->tx_loop.pending_record_lock);
 +	spin_lock_bh(&hw_priv->tx_loop.pending_record_lock);
         bes2600_queue_iterate_record_pending_packet(hw_priv, bes2600_tx_loop_item_pending_item);
 -	spin_unlock(&hw_priv->tx_loop.pending_record_lock);
 +	spin_unlock_bh(&hw_priv->tx_loop.pending_record_lock);
         if (atomic_read(&hw_priv->bh_rx) > 0)
 		wake_up(&hw_priv->bh_wq);
 -- 
 2.54.0
@@ -0,0 +1,47 @@
 From 0792ba44bb2f60e6f83e031364ee20739be71d01 Mon Sep 17 00:00:00 2001
 From: Markus Fritsche <fritsche.markus@gmail.com>
 Date: Wed, 20 May 2026 20:29:43 +0200
 Subject: [PATCH 20/20] bes2600: export bus_reset helpers for danctnix
 bes2600_btuart (danctnix-flavor)
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit
 bes2600_chrdev_do_bus_reset() and bes2600_chrdev_trigger_bus_reset() are
 already present (added by the connection-loss bus_reset commit) but not
 exported.  danctnix's bes2600_btuart.c uses these symbols for BT power
 switching and bus-error recovery; without EXPORT_SYMBOL_GPL the btuart
 module cannot be built as a separate object in the intree staging tree.
 The userspace /dev/bes2600 chardev remains intact for danctnix — btuart
 depends on the internal chardev state machine.  This commit is
 danctnix-specific; the Mobian DKMS flavor does not need the exports.
 Signed-off-by: Claude (noether) <claude@reauktion.de>
 ---
 bes2600/bes_chardev.c | 2 ++
 1 file changed, 2 insertions(+)
 diff --git a/drivers/staging/bes2600/bes_chardev.c b/drivers/staging/bes2600/bes_chardev.c
 index 801e4bf..35696af 100644
 --- a/drivers/staging/bes2600/bes_chardev.c
 +++ b/drivers/staging/bes2600/bes_chardev.c
@@ -1116,6 +1116,7 @@ int bes2600_chrdev_do_bus_reset(const struct sbus_ops *sbus_ops, struct sbus_pri
 	return 0;
 }
 +EXPORT_SYMBOL_GPL(bes2600_chrdev_do_bus_reset);
 /*
  * Trigger bes2600_chrdev_do_bus_reset() against the file-global
@@ -1128,6 +1129,7 @@ int bes2600_chrdev_trigger_bus_reset(void)
 	return bes2600_chrdev_do_bus_reset(bes2600_cdev.sbus_ops,
 					   bes2600_cdev.sbus_priv);
 }
 +EXPORT_SYMBOL_GPL(bes2600_chrdev_trigger_bus_reset);
 bool bes2600_chrdev_is_wifi_opened(void)
 {
 -- 
 2.54.0
@@ -0,0 +1,270 @@
 # Maintainer: Markus Fritsche <fritsche.markus@gmail.com>
 # Forked from: linux-pinetab2 by Danct12 <danct12@disroot.org>
 # Original Contributor: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
 #
 # linux-pinetab2-danctnix-besser: linux-pinetab2 + the BESser
 # bes2600 driver patchset (race-fix, lock-removal, attribution-restore,
 # fossil-cleanup; +73% throughput vs the in-tree baseline).  Soft-upstream
 # fork of linux-pinetab2 — drop-in replacement, same kernel version, only
 # the bes2600 staging driver differs.  See git.reauktion.de/marfrit/besser
 # and git.reauktion.de/marfrit/bes2600-dkms for full provenance.
 pkgbase=linux-pinetab2-danctnix-besser
 pkgver=7.0.danctnix1
 pkgrel=4
 pkgdesc='PineTab2 (BESser bes2600 driver patchset)'
 _srcname=linux-pinetab2
 _srctag=v${pkgver%.*}-${pkgver##*.}
 arch=(aarch64)
 _url_git="https://codeberg.org/DanctNIX/${_srcname}"
 url="${_url_git}/commits/tag/$_srctag"
 license=(GPL-2.0-only)
 makedepends=(
  bc
  cpio
  gettext
  git
  libelf
  pahole
  perl
  python
  tar
  xz
 )
 options=(
  !debug
  !strip
 )
 source=(
  https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/linux-${pkgver%.*}.tar.{xz,sign}
  ${_url_git}/releases/download/${_srctag}/${_srctag}.patch.zst{,.sig}
  0001-bes2600-defer-scan-and-soften-WARN-on-firmware-rejec.patch
  0002-bes2600-widen-scan-defer-backoff-to-30s-and-decay-co.patch
  0003-bes2600-recover-wedged-firmware-via-mmc_hw_reset-on-.patch
  0004-bes2600-gate-PM-indication-completion-on-pending-req.patch
  0005-bes2600-short-circuit-wake-handshake-when-chip-is-co.patch
  0006-bes2600-self-detect-when-firmware-does-not-honor-PSM.patch
  0007-bes2600-handle-multi-function-SDIO-cards-in-mmc_hw_r.patch
  0008-bes2600-pre-empt-AP-deauth-6-with-mac80211-reassoc-o.patch
  0009-bes2600-bus_reset-on-connection-loss-storm-to-dodge-.patch
  0010-bes2600-replace-a-set-of-atomic_add.patch
  0011-bes2600-fix-missing-destroy_workqueue-on-error-in-in.patch
  0012-bes2600-fix-concurrency-UAF-in-bes2600_hw_scan-and-s.patch
  0013-bes2600-drop-sdio_rx_work-relay-IRQ-bh-direct-no-rel.patch
  0014-bes2600-Patch-G-restore-SPDX-identifiers-ST-Ericsson.patch
  0015-bes2600-Patch-D-atomicize-ba_lock-counters-drop-the-.patch
  0016-bes2600-Patch-E-skip-ps_state_lock-when-PSM-known-di.patch
  0017-bes2600-Patch-C2-replace-ieee80211_rx_irqsafe-with-i.patch
  0018-bes2600-Patch-H-bh.c-hygiene-cleanup-drop-fossil-blo.patch
  0019-bes2600-take-pending_record_lock-with-_bh-to-fix-SOF.patch
  0020-bes2600-export-bus_reset-helpers-for-danctnix-bes260.patch
  0002-bes2600-filter-5ghz-scan.patch
  config  # the main kernel config file
 )
 validpgpkeys=(
  ABAF11C65A2970B130ABE3C479BE3E4300411886  # Linus Torvalds
  647F28654894E3BD457199BE38DBBDC86092693E  # Greg Kroah-Hartman
  F09A933C0FE0331E558CA4E166CAB7EAA45DD781  # Danct12
 )
 b2sums=('3d9795083c8938f80f480de0d10bfd9c525640e59d5c7f22983de3f12ee42c84c31be902cafb05579ddb1c32bac5ed06b0d4953f9705450be185bd2d9ab08f89'
        'SKIP'
        '71fe98221e802b315e54b4b10d3e8c8f376695a36bae3541d876e5776a37f3fa33c8f8dfa6e51fcbd6f5396add02e5166634165f2351836a0ea0453c172fe56c'
        'SKIP'
        '5268f55c132441e1ef2e0042e48940a51556286c2e2813c99e983bf89606c2aa05df56e42ebd8bcfd201ceaf63493ca3f2639a39f926e8419b3bc27a4ac4aced'
        'ebf786a401b5883431068b7a88ff1890ff4f2936cfceb6560828ba202a548c0c6f1f89d721837f1b67e85165d4dd1a2973cbe97e396e1b258efe5288a17d1a81'
        'ddf0f8c052f7d40f324791353b3831827cdb80da4726fb5596a0e61d6f194e84cbd0ceb036e22cb89a1af2baccb15ef7850621799d90e96a4049f9b11fc61565'
        'c811e415a549100da927e2caa4ef46ccdd6b2b834b0a781db6ca232a12d90278744133e19916de6421be2f95780b2978ec10eb620fe81a9697df3f2539b5747a'
        '4c28c0ee7443445986a4631d61e9c9f82944c4fd8380d6ba28a14dc85c8e641e88407f25c8abeb47000db25e267946a0d401d0bae4ad1c0b91e4f13953ad0081'
        '597b648ef625aff58fab7ca2067c303c1b7abdf03b78296c7b656260982eaded1938f294975abda75e864499f2bad4801941ff7acc5713d2628ae6550c9ecea3'
        '0f6e20acb800f55c853307a4fe9129280fd440a2b5214c068d91d3dbe5e7e207466ca5019d1792800ac9e4f072f006a5bbcb9b4004700426fc8f2eac6cbef5b2'
        'b793908df0483e64d98e91c7cae1496668f2597d5b6669e2f313abd3a648ba4a685562338e649cbe12a33ab142c90a129f9d642309ee38ad188cbc92fe99ae84'
        '3a41ced2ebbc6773fc4f2803ac835b7e839d81bae529c84191355ad2768065c2ef5e67a165af6bed29c0775c608869425bd1d20c8e2632faceac5bfa8ecb18d5'
        '2aa236f4a72712b974f3d4870ff6557892df8e05c748bc89a195284a3ab7330e0859a52815ee1c4447fd64365283117301fced72b590ea1d16cfc450cfd07018'
        '8c0de659c5dcb70cd6d993c9c8b7607476491440fa62a26a9aea4ee075e20016fe05ce8023c43125bd82b7f8879b20537a0d74e5de2d1b7211b5b37e787b48aa'
        '6e343e15b14ccc980e5ff21641051db57c8c8cb0705426403c0d0e2f7d1adf3efb79f331c34a5e1714ac5103b28e073404229588d8042ab5b8bb95c9ef8421a2'
        '54c9529e1d4fe55d028341fd761e24630f4f0a1c43b287db67bc878aa84ceca8e64283560399980bdcd10987ad3222c30e173e33ac1d341190d1237d6cf4f806'
        '0839ab95b408483774aaff978ece3a1e54ba8ec4bd8146cb2c649ee044224f3ad9c024bd534df09e6883e1d6d4b92593f7e168b6bd51bb32d9b3ee11f7b52716'
        '7b11001ba0638c24e36926a934448203c94240261742df999429954b9a5253e7e72ddda93d47c39b44e61b99491b83b7a46be2d098d3054bf92f73c226048715'
        '154a1a564a6d6ac316869456d271024c0af4cf7175c31579e6ac7293bdb20f413dcf5fd4684e63376627545c13c231ba2cbd28026684e33daec14e3751c25a1e'
        '4611b825d9a79589c427569f2d9521cc3c8d21603d7aae980b763414bbfd96c8d2ef04917805c0af4a8abf397228a866ff5f2c0540ae035662eb1f376bae5312'
        'e318299e4cb828220ac7d5142dc41969f22f83f1f791bd46f7f4ce19dbd1d7074b0faa9ac6a4daac4f70e6c7852b38a6482de62111bb7e653cd870d2968fce70'
        '5c71b88f2ae8a7ebd0932db9a4da72a3ba8c636f31a1bed953a81359588bcb0309f62aa9dee98db62bdc988a9b669341910da2b133d9fb92d14c27d64b54efe9'
        'e09273ddcdc44f4d40fe8a69e0fd70b963681ec4434ce63cf6114ea38954891e709ced877e0be914054854e2d295a2991e8c3d8dc0deb244bfc8b0568c681687'
        '396acbdcf570eada62533c0b8f505ed18077e8432249bab5b8ac8d1107cabc9489bdb91a5780446237ec4fd9ba5fc57a49dff34c16ddab60dc30513fc535f00f'
        '656a998ab40cb85ee4c00f087b071a91632a6c091da2c84b0f74236b51d2dea6e9db6886625f80ad81dc249d8494ec47cd79d6dd9ea4f5e44f3cde857f861e10')
 export KBUILD_BUILD_HOST=archlinux
 export KBUILD_BUILD_USER=$pkgbase
 export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"
 prepare() {
  cd linux-${pkgver%.*}
  echo "Setting version..."
  echo "-$pkgrel" > localversion.10-pkgrel
  echo "${pkgbase#linux}" > localversion.20-pkgname
  local src
  for src in "${source[@]}"; do
      src="${src%%::*}"
      src="${src##*/}"
      src="${src%.zst}"
      [[ $src = *.patch ]] || continue
      echo "Applying patch: $src..."
      patch -Np1 < "../$src"
  done
  echo "Setting config..."
  cp ../config .config
  make olddefconfig
  diff -u ../config .config || :
  make -s kernelrelease > version
  echo "Prepared $pkgbase version $(<version)"
 }
 build() {
  cd linux-${pkgver%.*}
  make DTC_FLAGS="-@" all
  make -C tools/bpf/bpftool vmlinux.h feature-clang-bpf-co-re=1
 }
 _package() {
  pkgdesc="The $pkgdesc kernel and modules"
  depends=(
    coreutils
    kmod
    mkinitcpio
  )
  optdepends=(
    'wireless-regdb: to set the correct wireless channels of your country'
    'linux-firmware: firmware images needed for some devices'
  )
  provides=(
    KSMBD-MODULE
    WIREGUARD-MODULE
    "linux-pinetab2=$pkgver-$pkgrel"
  )
  conflicts=(linux-pinetab2)
  replaces=(
    wireguard-arch
  )
  cd linux-${pkgver%.*}
  local modulesdir="$pkgdir/usr/lib/modules/$(<version)"
  echo "Installing boot image..."
  # systemd expects to find the kernel here to allow hibernation
  # https://github.com/systemd/systemd/commit/edda44605f06a41fb86b7ab8128dcf99161d2344
  install -Dm644 "$(make -s image_name)" "$modulesdir/vmlinuz"
  # Used by mkinitcpio to name the kernel
  echo "$pkgbase" | install -Dm644 /dev/stdin "$modulesdir/pkgbase"
  echo "Installing modules..."
  ZSTD_CLEVEL=19 make INSTALL_MOD_PATH="$pkgdir/usr" INSTALL_MOD_STRIP=1 \
    DEPMOD=/doesnt/exist modules_install  # Suppress depmod
  echo "Installing device trees..."
  make INSTALL_DTBS_PATH="$pkgdir/boot/dtbs" dtbs_install
  # Removing unnecessary device trees (keep only pinetab2 variants).
  # Use find -delete instead of a bash for-loop: the previous for-loop
  # silently no-op'd in the makepkg environment, leaving 234 unrelated
  # board DTBs in the package.  find is robust to nullglob/cwd quirks.
  find "$pkgdir"/boot/dtbs/rockchip/ -mindepth 1 -maxdepth 1 -type f \
       ! -name 'rk3566-pinetab2-*' -delete
  # remove build link
  rm "$modulesdir"/build
 }
 _package-headers() {
  pkgdesc="Headers and scripts for building modules for the $pkgdesc kernel"
  depends=(pahole)
  cd linux-${pkgver%.*}
  local builddir="$pkgdir/usr/lib/modules/$(<version)/build"
  echo "Installing build files..."
  install -Dt "$builddir" -m644 .config Makefile Module.symvers System.map \
    localversion.* version vmlinux tools/bpf/bpftool/vmlinux.h
  install -Dt "$builddir/kernel" -m644 kernel/Makefile
  install -Dt "$builddir/arch/arm64" -m644 arch/arm64/Makefile
  cp -t "$builddir" -a scripts
  # required when DEBUG_INFO_BTF_MODULES is enabled
  install -Dt "$builddir/tools/bpf/resolve_btfids" tools/bpf/resolve_btfids/resolve_btfids
  echo "Installing headers..."
  cp -t "$builddir" -a include
  cp -t "$builddir/arch/arm64" -a arch/arm64/include
  install -Dt "$builddir/arch/arm64/kernel" -m644 arch/arm64/kernel/asm-offsets.s
  install -Dt "$builddir/drivers/md" -m644 drivers/md/*.h
  install -Dt "$builddir/net/mac80211" -m644 net/mac80211/*.h
  # https://bugs.archlinux.org/task/13146
  install -Dt "$builddir/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h
  # https://bugs.archlinux.org/task/20402
  install -Dt "$builddir/drivers/media/usb/dvb-usb" -m644 drivers/media/usb/dvb-usb/*.h
  install -Dt "$builddir/drivers/media/dvb-frontends" -m644 drivers/media/dvb-frontends/*.h
  install -Dt "$builddir/drivers/media/tuners" -m644 drivers/media/tuners/*.h
  # https://bugs.archlinux.org/task/71392
  install -Dt "$builddir/drivers/iio/common/hid-sensors" -m644 drivers/iio/common/hid-sensors/*.h
  echo "Installing KConfig files..."
  find . -name 'Kconfig*' -exec install -Dm644 {} "$builddir/{}" \;
  echo "Removing unneeded architectures..."
  local arch
  for arch in "$builddir"/arch/*/; do
    [[ $arch = */arm64/ ]] && continue
    echo "Removing $(basename "$arch")"
    rm -r "$arch"
  done
  echo "Removing documentation..."
  rm -r "$builddir/Documentation"
  echo "Removing broken symlinks..."
  find -L "$builddir" -type l -printf 'Removing %P\n' -delete
  echo "Removing loose objects..."
  find "$builddir" -type f -name '*.o' -printf 'Removing %P\n' -delete
  echo "Stripping build tools..."
  local file
  while read -rd '' file; do
    case "$(file -Sib "$file")" in
      application/x-sharedlib\;*)      # Libraries (.so)
        strip -v $STRIP_SHARED "$file" ;;
      application/x-archive\;*)        # Libraries (.a)
        strip -v $STRIP_STATIC "$file" ;;
      application/x-executable\;*)     # Binaries
        strip -v $STRIP_BINARIES "$file" ;;
      application/x-pie-executable\;*) # Relocatable binaries
        strip -v $STRIP_SHARED "$file" ;;
    esac
  done < <(find "$builddir" -type f -perm -u+x ! -name vmlinux -print0)
  echo "Stripping vmlinux..."
  strip -v $STRIP_STATIC "$builddir/vmlinux"
  echo "Adding symlink..."
  mkdir -p "$pkgdir/usr/src"
  ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase"
 }
 pkgname=(
  "$pkgbase"
  "$pkgbase-headers"
 )
 for _p in "${pkgname[@]}"; do
  eval "package_$_p() {
    $(declare -f "_package${_p#$pkgbase}")
    _package${_p#$pkgbase}
  }"
 done
@@ -0,0 +1,108 @@
 # Bug #5 RX-degradation campaign — Phase 0
 **Date:** 2026-05-07
 **Module under test:** v3 + F (`bes2600.ko` srcversion `371C6606B73AF19299228CA`)
 **Hardware:** ohm (PineTab2, RK3566 + BES2600 SDIO), wired enu1 fallback path live.
 ---
 ## Research question (locked)
 > **Why does the bes2600 RX path collapse from ~2 MB/s sustained @ fresh-chip uptime to ~180 B/s @ ~28-min uptime, with periodic `wsm_generic_confirm failed for request 0x0007` + `ieee80211 phy0: [SCAN] Scan failed (-22)` every 300 s in the intervening window?**
 Reproduces on Patch B, Patch F, and Patch C v3 alike — independent of the relay/race issues v3 addressed. Side-effect that was masked by the throughput floor while v2's race was the dominant variable.
 ## Predecessor data (reference, not anchor)
 | source | observation |
 |---|---|
 | Patch C v3 N=3 (uptime 200/391/582 s) | mean 2.352 MB/s @ 4 MB/s sender |
 | v3 single rep at uptime ~28 min (rep 2 of 2026-05-07 22:23) | 180 KB / 5 min = 600 B/s, sender saw "Connection reset by peer" |
 | v3 single rep at uptime ~47 min (N=3 first attempt 22:42) | 55 KB / 5 min = 180 B/s, sender timed out (exit 124) |
 | dmesg pattern observed at 47-min uptime | scan failures every 301-302 s starting at uptime 778 s (~13 min) |
 The shape: **fresh chip → linear data flow at ~2 MB/s sustained → sometime around 13 min uptime, NetworkManager-triggered scans start failing → sometime around 28 min uptime, data throughput collapses to <1 KB/s while link still shows associated.**
 Predecessor data is reference. Phase 0 will re-anchor at N=1 long-trace + 5 in-window stress probes; if the pattern doesn't reproduce, that's the campaign result.
 ## Mechanism candidates (Phase 4 will discriminate)
 1. **Firmware-side resource exhaustion.** Per-scan or per-WSM-event accumulation in chip-side state. Scan-failed -22 (EINVAL) suggests firmware refusing the request — possibly out of scan handles, scan-buffer slots, or some other limit.
 2. **NetworkManager scan-fail recovery loop.** Each failed scan triggers NM retry. If retry overhead dominates the bh thread, data path starves. Verifiable by suppressing NM scans.
 3. **AP-side rate limiting.** Newton (AVM) AP could be applying QoS / fairness / probation after sustained 4 MB/s burst. Verifiable by Fritz!Box log access (Markus has it) or by switching to a different AP.
 4. **PSM state machine deadlock.** c7's `pm_unsupported` self-detect was supposed to handle this, but the latch state could become stale if a real PM_IND arrives mid-operation. Verifiable by `chip_pm_state` debugfs read at degradation onset.
 5. **SDIO bus clock degradation / mmc retune.** SDIO retune with `retune_protected` flag interacts with bes2600's data path. Verifiable by ftrace `mmc/mmc_request_*` event correlation with throughput drop.
 6. **Power-management busy-event accumulation.** `bes2600_pwr_set_busy_event` counters might leak — busy events not cleared lock the chip awake (no PSM) but also exhaust event capacity. Verifiable by `bes2600_pwr_busy_event_record` dump.
 ## Phase 0 measurement protocol (rig armed 2026-05-07 23:18:58 CEST, T0=1778188738)
 Capturing for 35 minutes from fresh boot. All capture lives in `/root/bes2600-samples/run-20260507-bug5-degradation-rig/` on ohm.
 ### Always-on streams
 | stream | tool | output |
 |---|---|---|
 | ftrace events | per-event `enable=1` | `trace.log` (via `trace_pipe`) |
 | cfg80211 events | `iw event -t -f` | `iw-event.log` |
 | kernel printks | `dmesg -wT` | `dmesg.log` |
 | netdev counters | per-30s shell loop | `snap.log` |
 ### ftrace event set
 - `workqueue/workqueue_execute_start` — work dispatches
 - `workqueue/workqueue_queue_work` — work submissions
 - `mac80211/api_beacon_loss` — driver beacon-loss events
 - `mac80211/api_connection_loss` — driver-side conn-loss
 - `mac80211/api_disconnect` — driver-side disconnect
 - `mac80211/drv_hw_scan` — mac80211 → driver scan dispatch
 - `mac80211/drv_set_key` — key state changes
 - `cfg80211/rdev_assoc` — assoc requests
 - `cfg80211/rdev_deauth` — deauth requests
 - `cfg80211/rdev_disassoc` — disassoc requests
 - `cfg80211/cfg80211_assoc_comeback` — AP-side assoc-busy throttling
 - `cfg80211/cfg80211_send_auth_timeout` — auth timeouts
 - `cfg80211/cfg80211_scan_done` — scan completions
 - `power/suspend_resume` — PM transitions
 - `mmc/mmc_request_start` / `mmc_request_done` — bus-level transactions
 ### Scheduled stress probes
 Sender on boltzmann (`/tmp/bug5-probe-loop.sh`) fires `pv -L 4m | nc ohm 12345` for 30 s at T+5/10/15/20/25 min. Each probe brackets uptime, RX-bytes pre, RX-bytes post, elapsed. Throughput-vs-uptime curve falls out of the snap.log + probe boundaries.
 Probe markers logged via `logger -t bes2600-bug5 PROBE_N_START/END` so they appear in dmesg.log timeline.
 ## Anti-theatre receipts (must tick before claiming Phase 0 done)
 - [ ] In-session baseline: long-capture across degradation window, N=1 for now; re-run if anomalous
 - [ ] ftrace events actually firing (verify by tail of trace.log mid-capture)
 - [ ] dmesg captures the scan-failure pattern timestamp (expected ~uptime 778 s)
 - [ ] Probes actually transferred data at fresh chip (T+5 should be > 1 MB/s)
 - [ ] At least one probe in-window after scan-failure onset (expected: T+15 or T+20)
 - [ ] Snap.log shows monotonic counter behaviour (no rx_bytes going backwards)
 ## Phase 1 hypothesis (provisional, refine after Phase 3 data)
 Metric candidate: **probe throughput as function of uptime, with state-transition markers (first `wsm_generic_confirm 0x0007 failed`, first `[SCAN] Scan failed (-22)`, first NetworkManager-deauth-and-reassociate)**.
 Discriminator question: does throughput collapse abruptly at the first scan failure, or gradually over a window? Abrupt = single-event causation; gradual = accumulator.
 ## Phase 4 candidates (post-Phase-3)
 Depending on which mechanism (1-6) Phase 3 surfaces:
 - (1) firmware resource exhaustion: report to upstream; possibly disable NetworkManager scans pending firmware fix.
 - (2) NM scan-fail loop: configure `wpa_supplicant` to skip scans; or add scan-failure handling in driver to dampen retry cascade.
 - (3) AP-side: switch APs for testing; report to AVM if reproducible.
 - (4) PSM deadlock: extend c7 latch with timeout-or-progress recovery.
 - (5) SDIO retune: ftrace correlation guides the lock-ordering fix.
 - (6) PWR busy-event leak: audit set/clear pairs; add a warning-when-stale.
 ## Out-of-scope
 - Patch C v3 closure (PR #5 merged, Phase 7 done).
 - Patch C2 (`ieee80211_rx_list` batch) — gated on Task #19 kerneldoc.
 - Patch D / E independent.
 - Reproduction at higher rates (8 MB/s ramp) — defer to Phase 4 once mechanism identified.
 ---
 *Phase 0 plan written 2026-05-07 23:21 CEST by Claude (noether), at the close of Patch C v3 Phase 7.  Rig armed; long capture in flight; probes scheduled at T+5/10/15/20/25 min.  Post-capture analysis will populate Phase 3 results before Phase 4 plan branches off.*
@@ -0,0 +1,184 @@
 # Patch C — Phase 4 Plan: collapse sdio_rx_work into BH
 **Author:** Claude (noether)
 **Status:** Phase 4 — pending Phase 5 second-model review before any Phase 6 code.
 **Scope:** **item 1 only** (per merged PR #8 inline review: "do it sequentially; we're not on the clock").
 **Item 2** (batch deliver via `ieee80211_rx_list`) splits to **Patch C2**, gated on Task #19 kerneldoc verification.
 ---
 ## §0 Substrate — anchored
 Bug #5 anchor (recorded 2026-05-07, see `notes/phase1-bug5-2026-05-07.md`):
 - Sender: netcat-over-WiFi, 4 MB/s cap, 2.4 GHz, AVM AP, single-STA
 - Receiver: ohm (PineTab2, RK3566 + BES2600WM-SDIO)
 - N=3 baseline reps: 725 / 663 / 75 KB/s (rep 3 saw link-death at ~9 min)
 - `perf record -g` during 4MB/s window: `_raw_spin_unlock_irqrestore` ≈ 20% CPU
 - ftrace lock-instrumentation, system-wide: `workqueue_execute_start` ≈ 5,643/sec
 - Driver-side count: `wsm_cmd_send` 13/sec — wsm command path is *not* the dispatch source; the contributor is the per-SDIO-transaction relay.
 Root cause traced in PR #7 (Sonnet review) and concurred in PR #8 (Opus review): RX path adds two synchronization points per frame and one wait-queue wake-up per IRQ batch via `sdio_rx_work` → `rx_queue` → `bh_work` indirection.
 ## §1 Goal (locked)
 Reduce per-RX-frame overhead enough that observed receive ≥ 1.0 MB/s sustained @ 4 MB/s sender, with `_raw_spin_unlock_irqrestore` < 15 % CPU during the 4 MB/s window. No 30-min cascade to link-death.
 (This is a partial step toward Phase 1's full target of ≥ 2 MB/s sustained @ 4 MB/s with < 10 % lock CPU. The full target is jointly addressed by Patch C + Patch C2; Patch C alone should *cross half the gap*.)
 ## §2 Situation
 - `bes2600.ko` srcversion `1B3B3ED0…` deployed on ohm (c-stack + Patch A + Patch B).
 - `cleanups` branch on `marfrit/bes2600-dkms` is the current source-of-truth.
 - Build sandbox `/var/tmp/c6-sandbox/` on ohm, native `make -j4`.
 - `BES2600_RX_IN_BH` is **defined** in Makefile — `bes2600_bh_rx_helper` is the active RX consumer.
 - ohm reachable. Markus pushes the reboot button; never me.
 - Test rig under `/root/bes2600-samples/` — `rep-trace.sh` per-rep capture script.
 ## §3 Baseline measurements
 Reused from Bug #5 Phase 0 (above). No re-anchor needed for Patch C — same regime.
 **Specific Phase-3-units that this plan's predictions reference:**
 | metric | tool | current value (4MB/s window) |
 |---|---|---|
 | observed receive throughput | netcat receiver byte-count | 75–725 KB/s, rep-variance high |
 | `_raw_spin_unlock_irqrestore` CPU% | perf record / report | ~20% |
 | `workqueue_execute_start`/sec | ftrace `workqueue:workqueue_execute_start` | ~5,643/sec system-wide |
 | `bes_sdio` workqueue dispatches | `cat /sys/kernel/tracing/events/workqueue/.../filter` filtered by `bes_sdio` | not measured pre-patch — **TODO before Phase 6** |
 | RX SKB rate at mac80211 boundary | trace `mac80211:drv_rx_irqsafe` count | not measured pre-patch — **TODO before Phase 6** |
 Phase 6 must not start until the two TODOs above are filled in — otherwise Phase 7 has no reference point for the predicted-delta comparison.
 ## §4 Plan
 ### §4.1 What will be touched
 - `bes2600_sdio.c::sdio_rx_work` — the relay loop. After this patch, it still drains the SDIO bus into SKBs but **delivers SKBs directly into `wsm_handle_rx`** instead of `skb_queue_tail`-ing them onto `self->rx_queue`.
 - `bes2600_sdio.c::bes2600_sdio_extract_packets` — the inner per-SKB extractor. Changes the in-loop action from `skb_queue_tail(&self->rx_queue, skb)` to a direct call (or callback) into the wsm dispatcher.
 - `bes2600_sdio.c::bes2600_sdio_pipe_read` — becomes unused, removed.
 - `bh.c::bes2600_bh_rx_helper` — its `BES_SDIO_RX_MULTIPLE_ENABLE` branch is no longer reachable for RX (RX path no longer feeds bh). Either gate the helper, or remove the helper outright if `bh_rx` atomic is no longer raised on RX.
 ### §4.2 What will NOT be touched
 - `ieee80211_rx_irqsafe()` call sites — that's Patch C2 (item 2).
 - TX path — `sdio_tx_work`, `bes2600_bh_tx_helper`, etc. Untouched.
 - `sdio_wq` workqueue alloc — stays. After patch it hosts only `tx_work` + `scan_work` + (briefly during patch) `rx_work`. Renaming is cosmetic and out of scope.
 - The bh thread itself — still runs, still handles TX, still watches the timeouts.
 - `bh.c` `#if 0` graveyard — separate hygiene patch, not bundled.
 - `__bes2600_irq_enable(1)` commented-out / `asm volatile("nop")` placeholder — **deferred** per `feedback_dont_patch_downstream_artifacts`. These are symptom-shaped; Patch C may dissolve them. Re-evaluate at Task #24 (post-Patch-E observation).
 - `bh_rx` / `bh_tx` atomic split — out of scope.
 ### §4.3 Approach choice — Option A (sdio_rx_work direct delivery)
 Two structural options surveyed in PR #8 §2.1; recap:
 | | Option A: direct delivery from sdio_rx_work | Option B: subsume sdio_rx_work into bh thread |
 |---|---|---|
 | diff size | small | medium |
 | eliminates `rx_queue->lock` × 2 per frame | yes | yes |
 | eliminates `sdio_wq.rx_work` workqueue dispatch per IRQ | no | yes |
 | changes who calls `wsm_handle_rx` | sdio_wq context (already process context) | bh thread |
 | TX/RX SDIO bus contention | unchanged (sdio_rx_work and sdio_tx_work already share `bes2600_sdio_lock`) | adds bh ↔ sdio_tx_work contention on the SDIO mutex |
 | bisection isolation | clean: only the rx_queue handoff is removed | mixes "remove handoff" with "subsume thread" |
 **Choosing Option A.** Reasons:
 1. Smaller diff = clearer Phase-7 attribution. If RX KB/s rises, we know it was the rx_queue handoff, not the workqueue topology.
 2. Per Markus's PR #8 review: split was for bisection clarity. Option A is narrower than Option B.
 3. The remaining cost (per-IRQ `sdio_wq.rx_work` dispatch) is ≤ 1 dispatch per IRQ batch; multi-RX coalescing means several frames per dispatch. If Phase 7 of Patch C shows that dispatch IS the residual cost, that becomes a concrete data point and motivates a *measured* Option-B follow-up, not a speculative one.
 ### §4.4 Implementation sketch (preview — actual code in Phase 6)
 **Today** (`bes2600_sdio.c:783–831`):
 ```c
 static int bes2600_sdio_extract_packets(...) {
    for each packet:
        skb = dev_alloc_skb(...);
        memcpy(skb->data, &data[pos], packet_len);
        spin_lock(&self->rx_queue_lock);
        skb_queue_tail(&self->rx_queue, skb);    // ← handoff
        spin_unlock(&self->rx_queue_lock);
 }
 static void sdio_rx_work(...) {
    bes2600_sdio_extract_packets(...);
    self->irq_handler(self->irq_priv);           // ← wakes bh_wq
 }
 // bh thread later: pipe_read = skb_dequeue(rx_queue) → wsm_handle_rx(skb)
 ```
 **After patch** (sketch):
 ```c
 static int bes2600_sdio_extract_packets(struct sbus_priv *self, u32 ctrl_reg, u8 *data) {
    for each packet:
        skb = dev_alloc_skb(...);
        memcpy(skb->data, &data[pos], packet_len);
        ret = wsm_handle_rx(self->core, wsm_id_from(skb), wsm_hdr_of(skb), &skb);
        if (skb) dev_kfree_skb(skb);
        // no rx_queue, no spinlock, no wake-up
 }
 static void sdio_rx_work(...) {
    bes2600_sdio_extract_packets(...);
    // self->irq_handler(...) is no longer called for RX-only wakes
    // (it remains called for TX-confirm-completion paths, if any)
 }
 ```
 Caveats discovered during sketch:
 - `wsm_handle_rx`'s signature wants `(hw_priv, id, wsm_hdr*, **skb)`. `extract_packets` doesn't currently parse the wsm header — we either parse it inline (cheap; the cost is one `__le16_to_cpu`) or defer parsing into a new `bes2600_sdio_deliver_rx(skb)` helper that wraps it.
 - `hw_priv` is reachable as `self->core`.
 - Need to verify `wsm_handle_rx` is callable from sdio_wq context. **Hypothesis:** yes, because today's bh thread is also process-context-via-workqueue and that's where wsm_handle_rx already runs. Phase 6 contract-cite from `wsm.h` / call-graph confirms.
 - The `irq_handler(self->irq_priv)` wakeup at sdio_rx_work:902 — keep it, but confirm whether bh actually has remaining work after RX is gone. Possibilities: TX-confirm completions (`wsm_release_tx_buffer`) still need a bh wake. Verify in Phase 6.
 ### §4.5 Predicted delta (Phase 3 units)
 Conservative because Patch C is item 1 only, not items 1+2.
 | metric | predicted change | confidence |
 |---|---|---|
 | `rx_queue->lock` acquire/release rate | → 0 (lock is removed entirely; struct field deleted) | high |
 | RX-path wait-queue wakes (`bh_wq` from sdio_rx_work for RX) | → 0 (TX-confirm wakes remain) | high |
 | `_raw_spin_unlock_irqrestore` CPU% | 20 % → 12–15 % | **medium** — the rx_queue lock is one of several contributors; I don't have per-lock breakdown pre-patch |
 | `workqueue_execute_start`/sec | marginal change (≤ 5 %) | high — sdio_wq dispatch still happens per IRQ |
 | observed receive @ 4 MB/s | floor lifts from 75 KB/s → ≥ 1.0 MB/s; rep-variance shrinks | **medium** — rep 3's link death has multiple causes (decrypt-storm path is Patch A's territory; AP-side `aid 30` rejection is also possible) |
 | Phase 7 N=3 outcome | all reps ≥ 1 MB/s sustained for 30 min @ 4 MB/s | **medium** |
 **Honest acknowledgement:** the medium-confidence predictions are the ones where Phase 7 either confirms the model or surfaces a new bug. If `_raw_spin_unlock_irqrestore` only drops to 18 %, the next-largest contributor was something else — `pool->lock` (workqueue infrastructure) or `ba_lock` — and Patch D/E/C2 become the answer.
 ### §4.6 Risks
 1. **`wsm_handle_rx` not callable from sdio_wq**: low probability (process context, same shape as today's bh), but a cite-failure here means revert to Option B. **Phase 6 must produce a `wsm.h` contract citation** before code lands.
 2. **TX-confirm wake-ups stop firing**: if `wsm_handle_rx` was the only thing that ultimately bumped `bh_tx`, removing it from bh's input causes TX-confirm starvation. Mitigation: keep `irq_handler(irq_priv)` call in sdio_rx_work for now; let the bh's wait_event re-evaluate `bh_tx` on every wake. **Verify in Phase 6 that `wsm_release_tx_buffer` still wakes bh.**
 3. **SKB allocation under memory pressure**: `dev_alloc_skb` in extract_packets currently `msleep(100)` retries up to 10×. Calling `wsm_handle_rx` directly from extract_packets keeps us in sdio_wq context during sleep; that's the same as today, so no new risk.
 4. **rcu / locking invariants in `wsm_handle_rx`**: it traverses `priv->vif_list`, may grab `priv->vif_lock`. Currently called from bh thread. After patch: called from sdio_wq context. Both are process context, both can sleep. No new risk *unless* there's a held lock at sdio_wq level that wsm_handle_rx tries to re-acquire. **Phase 6 lock-graph audit required.**
 5. **`bes2600_chrdev_is_bus_error()` early-return**: currently checked in `pipe_read`. After patch, must move into `extract_packets` or `sdio_rx_work` so RX during a bus-error window still gets dropped, not passed to mac80211.
 6. **Multi-vif RX serialization**: the `rx_queue` is per-sbus_priv, not per-vif. After patch, multi-vif demux happens inside `wsm_handle_rx` (same as today). No new risk; same ceiling.
 ### §4.7 Phase 5 review handover
 Goal/Situation/Measurements/Plan paste verbatim into DokuWiki when Markus initiates handover. **Do not curate** the plan for the reviewer — including the "medium-confidence" predictions and the §4.6 risk list verbatim. Reviewer should see the same uncertainty I have.
 ### §4.8 Phase 7 protocol (after Phase 6 lands)
 Per `feedback_phase7_stress_ramp.md` — **stress ramp, not steady cap**:
 1. Pre-patch baseline (re-anchor): 5 min @ 1 MB/s, 10 min @ 2 MB/s, 30 min @ 4 MB/s. Capture ftrace `workqueue/`, `lock/`, `mac80211/`, `mmc/`. perf record during the 4 MB/s window.
 2. Apply Patch C, install, reboot (Markus pushes).
 3. Post-patch: identical ramp, identical instrumentation.
 4. Compute deltas in **the same units** as §3 baseline. Compare to §4.5 predictions. Any unexplained delta is a finding, not a footnote — log it and loop back to Phase 4 if the model is wrong.
 5. **N=3 reps** post-patch. The user's stress-ramp memory and the receipts checklist both require this.
 6. Capture `sdio_work_debug` output and `dmesg` if any storm fires (Patch A's counter should hold steady).
 7. If Phase 7 numbers match prediction → Phase 8 memory update + proceed to Patch C2.
 8. If they don't match → loop back to Phase 4. Don't paper-fix.
 ## §5 Out-of-scope items recorded for follow-on patches
 - **Patch C2**: items 2 — `ieee80211_rx_list` batch delivery. Gated on Task #19 kerneldoc verification.
 - **Patch D**: ba_lock atomicization at `txrx.c:998-1005, 1632`. Independent.
 - **Patch E**: ps_state_lock skip when `pm_unsupported = true` at `txrx.c:1942-1948`. Independent, gated on c7 latch.
 - **Task #24**: post-Patch-E observation of bh.c `asm volatile("nop")`, commented-out `__bes2600_irq_enable(1)`, BUG_ON in steady-state hot path. Symptom-shaped; observe before patching.
 - **Task #25**: measure `sw_mci_check_r1_ready` on RK3566 during testing.
 ---
 *Plan written 2026-05-07 by Claude (noether). Awaiting Phase 5 second-model review on DokuWiki, initiated by Markus.*
@@ -0,0 +1,136 @@
 # Patch C v2 — Phase 4 Plan: atomic_t prep + direct-deliver
 **Author:** Claude (noether)
 **Status:** Phase 4 v2 — Phase 7 of Patch C (notes/patch-c-phase4-plan-2026-05-07.md, PR #9 merged) failed with a thread-safety race; this is the redesign.
 **Decision:** Option B from PR #3 close-out comment — `atomic_t` prep refactor first, direct-deliver on top.
 ---
 ## §0 What just happened (Phase 7 of Patch C)
 Reproduced verbatim from boot -1 of ohm 2026-05-07 20:18:10 CEST, ~13 s into a 4 MB/s nc stress:
 ```
 WARNING: at wsm_release_tx_buffer+0x84/0xa0 [bes2600], CPU#0: kworker/0:3H/3912
 Workqueue: bes_sdio sdio_rx_work [bes2600]
 pc : wsm_release_tx_buffer+0x84/0xa0 [bes2600]
 lr : bes2600_bh_handle_rx_skb+0x134/0x370 [bes2600]
 sdio_rx_work+0x2a8/0x540 [bes2600]
 bes2600_wlan: wsm_release_tx_buffer failed: -1
 ```
 Storm continued; chip wedged; ohm fell off the WiFi (wlan0).  Patch C module preserved at `/var/tmp/bes2600.patchC-broken.ko` for forensics.  Patch B rolled back, currently on disk on ohm.  Lesson saved as `feedback_phase6_contract_threadsafety` memory.
 ## §1 Why it failed
 `wsm_release_tx_buffer()` (bh.c:222–243) does **unlocked** read–modify–write on `hw_priv->hw_bufs_used`.  Pre-Patch-C invariant was single-writer = BH thread; the lock that mattered was structural, not annotated.  Patch C's direct-deliver moved one writer (RX-confirm decrement) into `sdio_rx_work` workqueue context.  BH thread + sdio_rx_work race on the int counter; underflow below zero, WARN, return -1, bookkeeping corrupt, TX wedges.
 Phase 6 contract block correctly cited `wsm_handle_rx`'s sleepability and held-lock invariants — but stopped at the called function's signature.  It did not enumerate `hw_bufs_used` as shared state mutated by the callee.  That's the gap.
 ## §2 Shared-state delta table (the thing missing from Patch C)
 Every field that `bes2600_bh_handle_rx_skb` mutates either directly or transitively, with current protection and required action:
 | field | declared at | written by (today) | written by (after Patch C v2) | current protection | action needed |
 |---|---|---|---|---|---|
 | `hw_priv->hw_bufs_used` | bes2600.h | `wsm_alloc_tx_buffer` (bh thread, TX submit), `wsm_release_tx_buffer` (bh thread, RX confirm), `main.c:543` (init) | + `wsm_release_tx_buffer` from sdio_rx_work | single-writer = BH thread (structural) | **convert to `atomic_t`** |
 | `hw_priv->hw_bufs_used_vif[i]` | bes2600.h | `wsm_release_vif_tx_buffer` (bh thread), `bh.c:1271` (vif TX submit), init | + `wsm_release_vif_tx_buffer` from sdio_rx_work | single-writer = BH thread | **convert to `atomic_t [N]`** |
 | `hw_priv->wsm_rx_seq[i]` | bes2600.h | bh thread RX | sdio_rx_work only | single-writer = BH/sdio_rx context (was BH, now is sdio_rx_work, but still **one writer**) | OK — single writer |
 | `hw_priv->wsm_tx_pending[i]` | bes2600.h | `bes2600_bh_inc_pending_count` (TX submit, BH thread), `bes2600_bh_dec_pending_count` (RX confirm) | dec moves to sdio_rx_work; inc stays BH | single-writer = BH | **also needs `atomic_t`** |
 | `hw_priv->lmac_mon_timer` / `mcu_mon_timer` | bes2600.h | mod_timer / del_timer_sync from BH | ditto from sdio_rx_work | timer API is internally locked | OK — `mod_timer` is concurrency-safe |
 | `hw_priv->wsm_cmd.lock` (taken inside wsm_handle_rx) | wsm_buf | bh thread (today) | sdio_rx_work | spinlock | OK — already protected |
 | `hw_priv->vif_lock` (taken inside wsm_handle_rx for some paths) | per vif | bh thread today | sdio_rx_work | spinlock | OK |
 | `priv->bh_evt_wq` wake-up | bes2600.h | wsm_release_tx_buffer when count hits 0 | ditto from sdio_rx_work | wake_up is concurrency-safe | OK |
 | `bes2600_pwr_clear_busy_event` (called inside release) | bes_pwr | bh thread | sdio_rx_work | internal locking via `bes_power.lock` | OK |
 | `hw_priv->buf_released` | bes2600.h | only `wsm_release_buffer_to_fw` (MCAST_FWDING ifdef, AP-only) | unchanged — BH only | single-writer = BH | OK — not on Patch C v2 hot path |
 **Three fields require atomic_t conversion:** `hw_bufs_used`, `hw_bufs_used_vif[]`, `wsm_tx_pending[]`.  Everything else is already concurrency-safe or moves cleanly to single-writer-in-sdio_rx_work.
 ## §3 Read-site survey (the rest of the work — atomic_read swaps)
 `grep -hE "hw_bufs_used\b|hw_bufs_used_vif\b" *.c *.h | wc -l` = **57 references** across the source tree:
 - 5 writers (above)
 - 52 readers — converted mechanically to `atomic_read()`.  Distribution:
  - `bh.c`: 22 read sites (most in the bh main loop, BUG_ON gates, idle / suspend predicates)
  - `sta.c`: 3 sites (PM idle check at sta.c:1231–1253)
  - `bes2600_sdio.c`: 1 site (PM idle check at line 958)
  - `main.c`: 2 sites (init zero, teardown wait)
  - `debug.c`: 1 site (debugfs stats)
  - `itp.c`: 1 site (test mode)
 `wsm_tx_pending[i]` site count is smaller — ~6 references, all in bh.c and the timer monitors.  Same mechanical conversion.
 ## §4 Plan v2 — two-step
 **Patch C-prep** (NFC, lands first):
 - Convert `hw_bufs_used` from `int` → `atomic_t`.
 - Convert `hw_bufs_used_vif[CW12XX_MAX_VIFS]` from `int[]` → `atomic_t[]`.
 - Convert `wsm_tx_pending[2]` from `int[]` → `atomic_t[]`.
 - Update writers:
  - `wsm_alloc_tx_buffer`: `atomic_inc(&hw_priv->hw_bufs_used)`.
  - `wsm_release_tx_buffer`: rewrite with `atomic_fetch_sub_release(count, &hw_priv->hw_bufs_used)` — returns prior value.  Re-derive the "tx restart" predicate (`prior >= numInpChBufs - 1`) and the "wake bh_evt_wq + clear busy" predicate (`prior - count == 0`) from that.  WARN if `prior - count < 0`.
  - `wsm_release_vif_tx_buffer`: same pattern on the array element.
  - `bes2600_bh_inc/dec_pending_count`: use `atomic_inc` and `atomic_dec_return` (need post-decrement value to decide whether to del_timer).
 - Update all 52+6 read sites: mechanical `atomic_read()` swap.
 - `main.c:543` init: `atomic_set(&hw_priv->hw_bufs_used_vif[i], 0)`.
 **Patch C-prep does NOT change behaviour.**  Same atomic ordering (`_release` / `_acquire` chosen to match the implicit memory ordering the BH-only path had).  Phase 7 of C-prep alone should show **identical** numbers to pre-patch baseline (`run-20260507-patchC-preflight`): 1.36 MB/s, 86.4 sdio_rx_work/sec, 90.3 dispatches per 1000 RX pkts, 0 bh_work redispatches.  If Phase 7 of C-prep shows a delta, the atomic ordering is wrong and we loop back here, not to C v2.
 **Patch C v2** (the actual structural change, lands on top of C-prep):
 - Identical to Patch C as merged in PR #3 (since closed): direct-deliver from `bes2600_sdio_extract_packets` into `bes2600_bh_handle_rx_skb`, no `rx_queue` indirection, no bh wake-up for RX.
 - The contract block in `bh.c::bes2600_bh_handle_rx_skb` is **expanded** to include the shared-state delta table from §2 of this plan, with explicit citations.
 - Same minimum-diff scope as Patch C: keep `rx_queue`, `pipe_read`, `bh_rx_helper` for clean bisection; remove in a follow-up hygiene patch.
 ## §5 What will NOT be touched (deferred or out of scope)
 - mac80211-side `ieee80211_rx_irqsafe` → `ieee80211_rx_list` migration: that's Patch C2, gated on Task #19 kerneldoc verification.
 - The `#if 0` graveyard in bh.c, the `asm volatile("nop")` placeholder, the BUG_ON in steady-state hot path: still symptom-shaped per `feedback_dont_patch_downstream_artifacts`.  Re-evaluate at Task #24 after C v2 / D / E land.
 - `ba_lock` (Patch D) and `ps_state_lock` (Patch E): independent.
 ## §6 Risk list (per Phase 6 contract-thread-safety memory)
 1. **C-prep memory ordering**: I've chosen `atomic_fetch_sub_release` for `wsm_release_tx_buffer` to mirror the implicit BH-thread ordering (release before subsequent atomic ops on `bh_evt_wq` / `bes_power`).  If the BH thread or other readers expect `_acquire` semantics on the value, we get reordering bugs that are hard to reproduce.  **Mitigation:** pair with `_acquire` reads where the read-then-decision pattern is critical (e.g., the bh main loop's `if (!hw_priv->hw_bufs_used)` idle predicate).  Cite the kerneldoc reference for `atomic_fetch_sub_release` in the commit message.
 2. **`wsm_tx_pending[]` decrement-side timer interaction**: `bes2600_bh_dec_pending_count` does `if (--hw_priv->wsm_tx_pending[idx] == 0) del_timer_sync(timer); else mod_timer(timer, ...)`.  After atomic_t conversion: `if (atomic_dec_return(&hw_priv->wsm_tx_pending[idx]) == 0) ...`.  But *another* thread could `atomic_inc` between our dec and the timer call, racing the del_timer.  `del_timer_sync` is internally safe (it can be called concurrently with `mod_timer`), but the **decision** "whether to delete vs mod" is racy.  **Mitigation:** even after atomic conversion, this function still needs to be called from a single context.  Verify `inc/dec_pending_count` callers — if both sides only fire from BH and sdio_rx_work and never overlap on the same idx, we're fine; if not, this needs a lock.
 3. **`hw_bufs_used_vif[]` array vs `wsm_alloc_tx_buffer`**: vif counter increment lives at bh.c:1271, called from bh thread TX-submit path.  Decrement (`wsm_release_vif_tx_buffer`) called from RX-confirm.  After Patch C v2 the decrement is in sdio_rx_work — same race shape as the global counter.  Already covered by the atomic_t array conversion.
 4. **PM idle predicate at sta.c:1239**: reads `hw_priv->hw_bufs_used_vif[priv->if_id]` to decide can-sleep.  Currently racy (was already reading BH-mutated state from a non-BH PM context).  Atomic conversion makes the read coherent.  PM context's read-then-decide is still fundamentally a snapshot — no change in semantics, just no torn-read.
 5. **Reboot / module-unload teardown** (`main.c:840`): `wait_event_timeout(... !hw_priv->hw_bufs_used ...)`.  Becomes `... !atomic_read(...)`.  No semantic change — the wait_event macro re-evaluates the predicate on each wake.
 6. **Phase 7 rig: Patch C v2 still wedges chip if I missed anything**: now mitigated by ohm's new wired interface (enu1, 192.168.88.80) — survives bes2600 wedges, lets us collect dmesg / ftrace / journalctl from a wedged ohm without reboot.  See `reference_ohm_wired_iface` memory.
 ## §7 Phase 5 review handover
 PR on git.reauktion.de/marfrit/besser, this file as the artifact (per `feedback_phase5_surface_is_pr`).  Specifically request reviewer focus on §2 shared-state delta table — that's the part that should have caught Patch C's bug.  Don't curate.
 ## §8 Phase 6 implementation order
 1. Branch off `cleanups` on bes2600-dkms-mobian: `bes2600/atomic-tx-buf-counters` (= Patch C-prep).
 2. Mechanical refactor: `int hw_bufs_used` → `atomic_t hw_bufs_used`, all reads → `atomic_read`, all writes → atomic ops.  Same for vif array and tx_pending array.  No other changes.
 3. Build, install, smoke-test.  Phase 7 of C-prep.  Should be a no-op delta.
 4. PR + Phase 5 review + merge.
 5. Branch off C-prep: `bes2600/sdio-rx-direct-deliver-v2` (= Patch C v2).
 6. Re-apply the Patch C delta (3 files: bh.h, bh.c, bes2600_sdio.c — same edits as PR #3).
 7. Build, install, Phase 7 N=3 stress ramp.
 8. PR + Phase 5 review + merge.
 ## §9 Phase 7 v2 protocol (per `feedback_phase7_stress_ramp` + wired-rig)
 1. Pre-C-prep baseline rep N=3 (re-anchor, since current N=1 baseline is from `run-20260507-patchC-preflight`).
 2. Apply C-prep, N=3.  Compare to pre.  Expect: zero meaningful delta.  If non-zero → memory-ordering bug, loop back to §4 atomic-ordering choice.
 3. Apply C v2, N=3.  Compare to C-prep baseline.  Expect: §4.5 of original Patch C plan's predicted delta (rx_queue lock acquires → 0, observed RX KB/s lifts toward ≥1 MB/s sustained @ 4MB/s).
 4. **All Phase 7 stress runs use the wired path (`ssh mfritsche@192.168.88.80`) for telemetry collection.**  When the chip wedges (it shouldn't this time, but planning for it), wlan0 stops responding but enu1 stays alive.  Collect dmesg / ftrace / journalctl over enu1 BEFORE rebooting.  This is the data we lost in Patch C boot -1 because wlan0 was the only path.
 5. N=3 reps per phase per `feedback_phase7_stress_ramp`.  Don't accept N=1 as verification.
 ## §10 Closeout
 If C-prep + C v2 both pass Phase 7: proceed to D (ba_lock atomicization), E (ps_state_lock skip).  Markus's "we're not on the clock" applies — sequencing per bisection clarity, not delivery deadline.
 ---
 *Plan written 2026-05-07 by Claude (noether), in response to Patch C Phase 7 failure.  Phase 5 review = PR comments on this artifact at git.reauktion.de/marfrit/besser.  Don't curate the shared-state delta table for the reviewer — that's the part the previous round's reviewer should have caught me on.*
@@ -0,0 +1,127 @@
 # Patch C v3 — Phase 4 Plan: drop sdio_rx_work, match cw1200 architecture
 **Author:** Claude (noether)
 **Status:** Phase 4 v3 — supersedes v2 (PR #10) after cw1200 mainline survey showed the race-free path is structural, not lock-based.
 **Decision:** drop the `sdio_rx_work` workqueue entirely; SDIO IRQ wakes `bh_wq`; bh thread does the SDIO read inline.  Restores single-writer-from-bh invariant on `hw_bufs_used` *by construction*.  No `atomic_t` prep needed.
 ---
 ## §0 Why v3 supersedes v2
 PR #10's plan was: convert `hw_bufs_used` etc. to `atomic_t` (prep), then direct-deliver from `sdio_rx_work` (structural).  That was a workaround for the race that *only existed because of the relay*.
 The cw1200 mining (`~/src/linux-rockchip`, 228 cw1200 commits) showed the upstream answer: there is no relay.  cw1200's IRQ handler bumps `bh_rx` and wakes the bh thread; the bh thread does the SDIO read itself inside `cw1200_bh_rx_helper` (`drivers/net/wireless/st/cw1200/bh.c:233`).  Single thread = single writer for `hw_bufs_used` = no race.  Same `int hw_bufs_used` as bes2600, never atomic_t'd in 16 years upstream because it never needed to be.
 Patch C v3 brings bes2600 into that shape.  The structural simplification is bigger than v2's diff but lands the right architecture in one move.
 ## §1 Goal
 Same as Patch C v2 §1: ≥ 1 MB/s sustained receive @ 4 MB/s sender, < 15 % `_raw_spin_unlock_irqrestore` CPU%, no 30-min cascade to link-death.  Stretch toward Phase 1's full 2 MB/s once Patch C2 (rx_list batch) lands separately.
 ## §2 Situation
 - Cleanups branch is at Patch F merged (commit `b717251`).  All Phase 5 reviews of the F series merged via PR #4.
 - ohm rebooted with F module live (srcversion `A9438692D6A8698F92AEEA1`) — F is the new baseline for Patch C v3 Phase 7 comparison.
 - Wired path `enu1` at `192.168.88.80` survives bes2600 wedges; lmcp `ohm` still goes through wlan0.  Phase 7 telemetry collection over enu1.
 - Reboot-permission override active (ohm dev-allocated; I can `sudo reboot` directly — `feedback_user_pushes_reboot_button` override clause).
 ## §3 Baseline measurements
 Carry forward from `run-20260507-patchC-preflight/baseline.tsv` (N=1, F-less Patch B module):
 | metric | value |
 |---|---|
 | observed receive @ 4 MB/s | 1.362 MB/s |
 | sdio_rx_work dispatches | 86.4/s = 90.3 per 1000 RX packets |
 | sdio_tx_work dispatches | 276.1/s |
 | bes2600_bh_work redispatches | 0 (single long-lived) |
 **Phase 6 prereq:** capture an N=3 baseline ON THE F MODULE before Patch C v3 code lands.  Same instrumentation, same stress ramp.  This is the post-F / pre-v3 reference.  Without it, Phase 7's delta is C+F vs B+nothing — confounded.
 ## §4 Plan v3
 ### §4.1 What gets eliminated
 - **`sdio_rx_work` (bes2600_sdio.c:829)** — function deleted.  No longer queued, no longer runs.
 - **`self->rx_work` work_struct** — field deleted from `struct sbus_priv`.  `INIT_WORK` removed.
 - **`self->rx_queue` + `self->rx_queue_lock`** — fields deleted.  `skb_queue_head_init` removed.  No SKB ever queued there.
 - **`bes2600_sdio_pipe_read`** — function deleted.  No callers after this patch.
 - **`sbus_ops->pipe_read`** — sbus op slot deleted (or kept and stubbed; tx_loop.c also implements it for the test-loop bus, has to stay if test-loop is preserved).
 - **`queue_work(self->sdio_wq, &self->rx_work)`** at the 3 call sites in `bes2600_sdio.c` (lines 416, 941, 1199) — removed.
 ### §4.2 What gets added
 - **A new `bes2600_bh_handle_rx_skb()`** in bh.c (same shape as Patch C added, same contract block; no longer needs to also wake the bh thread because we ARE the bh thread).
 - **A new helper `bes2600_sdio_read_rx_batch()`** in bes2600_sdio.c, exported, that does what `sdio_rx_work` used to do MINUS the queuing: lock → read ctrl_reg → memcpy_fromio → packets_check → for-each-frame extract+deliver.  Called from bh.
 ### §4.3 What gets rewired
 - **`bes2600_gpio_irq_handler`** in bes2600_sdio.c:413 (the GPIO-IRQ path used when CONFIG_BES2600_USE_GPIO_IRQ is set):  drop `queue_work(self->sdio_wq, &self->rx_work)`; instead call `self->irq_handler(self->irq_priv)` directly (which is `bes2600_irq_handler` in bh.c, bumps `bh_rx` + wakes `bh_wq`).  Matches cw1200_sdio_irq_handler shape.
 - **`bes2600_bh_rx_helper`** (bh.c:961, BES_SDIO_RX_MULTIPLE_ENABLE branch): instead of `pipe_read`-ing one SKB from the (now-gone) rx_queue, call the new `bes2600_sdio_read_rx_batch()` which does the SDIO read AND delivers each frame inline via `bes2600_bh_handle_rx_skb()`.  Returns count delivered, or negative on error.
 - **`bes2600_bh()` outer loop**:  after a successful rx_batch read, the helper signals whether to continue draining (more frames pending) — same shape as today's `BH_RX_CONT_LIMIT=3` outer loop.
 - **`bes2600_gpio_wakeup_mcu(SDIO_RX)`** + **`bes2600_gpio_allow_mcu_sleep(SDIO_RX)`** brackets:  currently called inside sdio_rx_work.  Move into bh thread around the `bes2600_sdio_read_rx_batch()` call.  Same wake-flag bracketing, just from a different thread.
 - **`sdio_wq` workqueue**:  keeps `tx_work` and (briefly) `scan_work`.  Renamed or kept — cosmetic.  Don't touch in this patch.
 ### §4.4 What stays untouched
 - TX path (`sdio_tx_work`, `bes2600_bh_tx_helper`, `wsm_alloc_tx_buffer`).  Independent.
 - WSM protocol layer (`wsm.c`, `wsm_handle_rx`).  Same callees, just from bh thread now.
 - mac80211 RX delivery (`ieee80211_rx_irqsafe`).  That's Patch C2.
 - `BES2600_RX_IN_BH` ifdef gate.  Stays defined; the gated branch is now the only RX path.
 - Symptom-shaped artifacts (asm nop, BUG_ON in hot path) — still deferred, see task #24 post-cleanup.
 ## §5 Shared-state delta table (the v2 lesson, applied)
 Every field `bes2600_bh_handle_rx_skb` mutates directly or transitively, with the v3 protection:
 | field | written by (today) | written by (after v3) | concurrency | required action |
 |---|---|---|---|---|
 | `hw_priv->hw_bufs_used` | bh thread (TX submit + RX confirm), main.c init | **bh thread only** (RX moves into bh) | single-writer | none — `int` is fine, race-free by construction |
 | `hw_priv->hw_bufs_used_vif[i]` | bh thread (TX vif submit + RX vif confirm), main.c init | **bh thread only** | single-writer | none |
 | `hw_priv->wsm_rx_seq[i]` | sdio_rx_work today | bh thread | single-writer | none — moves cleanly between contexts |
 | `hw_priv->wsm_tx_pending[i]` | bh thread (inc on TX submit), bh+sdio_rx_work (dec on RX confirm) | **bh thread only** | single-writer | none |
 | `hw_priv->lmac_mon_timer` / `mcu_mon_timer` | mod_timer / del_timer_sync from bh + sdio_rx_work | bh thread only | timer API safe anyway | none |
 | `hw_priv->wsm_cmd.lock` | spinlock taken inside wsm_handle_rx | same | already protected | none |
 | `priv->bh_evt_wq` wake-up | wsm_release_tx_buffer when count→0 | same | wake_up is concurrency-safe | none |
 | `bes_pwr.lock` (inside bes2600_pwr_clear_busy_event) | bh thread (today) | bh thread | already protected | none |
 | `self->rx_data_cnt` etc. (sbus_priv stats) | sdio_rx_work | bh thread | single-writer | none |
 **Zero fields require new locking.** The architectural pivot eliminates the race v2's atomic_t was working around.
 ## §6 Risks
 1. **bh thread now holds the SDIO bus mutex during read** (currently held by sdio_rx_work).  TX work in the same bh thread is unaffected (sdio_tx_work runs on a separate workqueue and shares the same mutex anyway).  The sdio_lock contention pattern doesn't change.
 2. **Loss of "parallelism" between sdio_rx_work and bh TX**:  sdio_rx_work and bh thread *appeared* to run in parallel today, but both serialize through `bes2600_sdio_lock(self)` for the actual bus operations.  The parallelism was illusory.  Net throughput should not regress.
 3. **bh thread CPU-busy-time per RX batch increases**:  inline SDIO read is the same cost, just charged to bh instead of sdio_wq's worker.  Mitigation: the per-IRQ workqueue dispatch cost (~86/s) is what we trade for it.  Net: -86 dispatches/s, +0 µs per frame.
 4. **Multi-RX coalescing (BES_SDIO_RX_MULTIPLE_NUM=16)** stays.  bes2600_sdio_extract_packets parses the multi-frame buffer same as before, just inline now.  No functional change to chip-side behaviour.
 5. **GPIO wake-flag bracketing**:  `bes2600_gpio_wakeup_mcu(SDIO_RX)` and `bes2600_gpio_allow_mcu_sleep(SDIO_RX)` currently bracket sdio_rx_work.  Move them to bracket the new bh-side read.  If the wake-flag accounting is sub-system-scoped (it is — flag bits per subsystem), this is a clean move.
 6. **IRQ re-enable in bh thread**:  cw1200's bh re-enables IRQ via `__cw1200_irq_enable(priv, 1)` after each round.  bes2600 has the analogous `__bes2600_irq_enable(0/1)` (commented out as the `asm volatile("nop")` symptom in `bh.c:1518-1520`).  This patch does NOT re-engage the commented-out re-enable — that's still task #24's call.  But if the IRQ stays disabled across rounds, we'd never receive the next IRQ.  **Investigate before Phase 6 lands**: where does IRQ re-enable happen in the current bes2600 hot path?  The sdio_func IRQ may be auto-managed by sdio core differently.  Block Phase 6 on this audit.
 7. **Phase 7 wedge resilience**:  if v3 has a different bug shape than v2's race (which it shouldn't, since the race is gone by construction), the wired path lets us collect telemetry from a wedged ohm.
 ## §7 Phase 5 / 6 / 7
 - **Phase 5**: PR on `git.reauktion.de/marfrit/besser` with this artifact.  Specifically request reviewer focus on §6 risk #6 (IRQ re-enable mechanism).
 - **Phase 6**: branch off cleanups (post-F): `bes2600/sdio-rx-no-relay`.  Implement the file changes per §4.  Build, install, smoke-test.
 - **Phase 7**: 
  - First: N=3 stress-ramp **on F module** (post-F pre-v3 baseline).  10 min @ 1, 30 min @ 2, 30 min @ 4 MB/s.  Use wired path for telemetry.
  - Then: install v3 module, identical N=3 ramp.  Compare deltas.
  - Predicted: sdio_rx_work dispatch rate → 0/s (was 86/s).  observed receive lifts toward ≥ 1.0 MB/s sustained.  `_raw_spin_unlock_irqrestore` drops by the rx_queue lock contribution (was 1914/s acquires).
 ## §8 What gets dropped from v2 plan
 - atomic_t prep refactor (`hw_bufs_used` → `atomic_t`): not needed.  Single-writer invariant preserved structurally.  Still a defensible standalone hardening patch *if mainlining bes2600 ever requires defense-in-depth*, but not on the Bug-#5 critical path.
 - `wsm_tx_pending[]` decrement-decision race (v2 risk #2): also moots.  Both sides single-thread under v3.
 - v2 Phase 7's "C-prep should show zero delta" gate: replaced by "v3 should match cw1200's structural shape" gate.
 ## §9 Open question for reviewer
 The big one is §6 risk #6 — IRQ re-enable. cw1200 explicitly does `__cw1200_irq_enable(priv, 1)` from bh after each round; bes2600 has the call **commented out** with an `asm volatile("nop")` placeholder.  Either:
 (a) bes2600's SDIO IRQ is level-triggered + auto-acked by SDIO core, so re-enable isn't needed (that would explain the nop).
 (b) The current code happens to work because sdio_rx_work is queued by the IRQ regardless of whether IRQ is "enabled" by the driver-side flag.  After v3 we have to manually re-enable like cw1200 does.
 Need to confirm (a) vs (b) before Phase 6 lands.  Plan to grep for `__bes2600_irq_enable` callsites and trace back to whether it's load-bearing.
 ---
 *Plan written 2026-05-07 by Claude (noether), after Patch F merged and Patch C v2 (PR #10) was superseded by the cw1200 architectural mining finding.  Phase 5 review on PR.  Don't curate.*
@@ -0,0 +1,171 @@
 # Patch C2 — Phase 4 Plan: migrate ieee80211_rx_irqsafe → ieee80211_rx_list
 **Author:** Claude (noether)
 **Status:** Phase 4 — pending Phase 5 PR review before any Phase 6 code.
 **Predecessor:** Patch C v3 (PR #5 merged, +73% throughput, no-relay architecture); Patch D + E + F + G also landed. Cleanups branch tip = 42fd0ce.
 **Task #19 contract**: `ieee80211_rx_list` callable from process context, **requires `local_bh_disable()` + `rcu_read_lock()` wrap**, **cannot mix with `ieee80211_rx_irqsafe()` for the same hardware** → all 6 sites convert in one shot.
 ---
 ## §0 Substrate
 After Patch C v3:
 - bh thread is the sole RX-delivery context (no relay, no sdio_rx_work)
 - Per-frame work runs in process context (sleepable)
 - Single-writer-from-bh invariant covers `hw_bufs_used` and friends
 `ieee80211_rx_irqsafe` is currently called from process context. Per kerneldoc (`include/net/mac80211.h:5399-5411`):
 > **Like ieee80211_rx() but can be called in IRQ context** (internally defers to a tasklet.)
 The tasklet hop is the cost we pay today for delivering each RX frame from process context. `ieee80211_rx_list` is the process-context replacement.
 ## §1 Goal
 Per-frame: skip the tasklet hop. Batch: process multiple SKBs from one SDIO read inside a single `local_bh_disable()`/`rcu_read_lock()` window.
 Phase 1 metric: **RX throughput @ 4 MB/s sender**, with v3 N=3 baseline = 2.352 MB/s. Hypothesis: small to moderate uplift (<10%) from removing the tasklet deferral. Larger improvement would be surprising — if observed, that's a finding to investigate.
 ## §2 Situation
 - 6 call sites in bes2600 currently use `ieee80211_rx_irqsafe`:
  - `ap.c:96` (AP-mode link-id RX queue drain)
  - `sta.c:1487` (link-id rx_queue drain in ?)
  - `txrx.c:1960` (early-data + pm_unsupported branch — Patch E added)
  - `txrx.c:1967` (early-data + LINK_SOFT-not-set branch)
  - `txrx.c:1971` (normal RX path)
  - `wsm.c:2415` (beacon SKB delivery from `bes2600_beacon_handler`?)
 - All 6 must convert together (kerneldoc: cannot mix per hardware)
 - bh thread is single-writer post-v3 → `_rx_list`'s "calls must be synchronized" satisfied trivially
 - bh thread is process context → `_rx_list` callable
 ## §3 Baseline (carry forward)
 From `notes/phase7-v3-2026-05-07.md` (v3 N=3 ramp, Phase 7 closed):
 | metric | v3 fresh-chip N=3 |
 |---|---|
 | RX throughput @ 4 MB/s | mean 2.352 MB/s, min 2.102, max 2.590 |
 | sdio_rx_work dispatches | 0/s |
 | bh_work redispatches | 0 |
 Phase 7 of C2 will compare against this baseline.
 ## §4 Plan
 ### §4.1 Conversion shape
 Per call site:
 ```c
 ieee80211_rx_irqsafe(priv->hw, skb);
 ```
 becomes:
 ```c
 ieee80211_rx_list(priv->hw, NULL, skb, &priv->rx_list);
 ```
 Where `priv->rx_list` is a `struct list_head` initialized once.
 **Wrap requirement:** `local_bh_disable()` + `rcu_read_lock()` must be held across the call. Per the kerneldoc, that's also needed for batch correctness.
 ### §4.2 Wrap placement (the design decision)
 **Option A — per-call wrap.** Wrap each individual `ieee80211_rx_list()` call. Simple but loses the batch benefit (each call's wrap+unwrap costs as much as the avoided tasklet defer).
 **Option B — per-batch wrap.** Wrap the OUTER frame-iteration loop (e.g., the `for` in `bes2600_sdio_extract_packets`). All 16 SKBs from one SDIO read get delivered inside one wrap. This is the upstream-idiomatic pattern (mt76, iwl_pcie do this).
 Choosing **Option B**. Concrete shape:
 - `bes2600_sdio_read_rx_batch` (the per-SDIO-batch entry point added in Patch C v3) wraps the read+extract+deliver phase:
  ```c
  rcu_read_lock();
  local_bh_disable();
  // existing read + extract_packets that calls bh_handle_rx_skb per frame
  local_bh_enable();
  rcu_read_unlock();
  ```
 - Inside `bes2600_bh_handle_rx_skb`, the single `ieee80211_rx_irqsafe` swap becomes `ieee80211_rx_list(priv->hw, NULL, skb, &priv->rx_list)`.
 - The OTHER 5 call sites (in `ap.c`, `sta.c`, `txrx.c`'s branches, `wsm.c`) need the same treatment, but they're called from the bh thread (post-v3) so they're already in the right context. Each gets its own narrow wrap (Option A applied selectively because those paths process one frame at a time, not a batch).
 ### §4.3 The `rx_list` field
 Add `struct list_head rx_list` to either `struct bes2600_common` (driver-wide) or `struct bes2600_vif` (per-vif). Per-vif is cleaner because the existing `priv->hw` parameter implies vif scope.
 `INIT_LIST_HEAD(&priv->rx_list)` at vif setup; no teardown needed (mac80211 owns the SKBs once handed off).
 **Open question for reviewer:** does the `rx_list` need to be drained explicitly after the batch (e.g., via a `list_for_each_entry_safe` + `netif_receive_skb_list_internal`)? Looking at mainline mt76 / iwl_pcie usage will clarify. Phase 6 must answer this before code lands.
 ### §4.4 What will NOT be touched
 - The 6 call sites change atomically (all-or-nothing per kerneldoc) — no per-site progressive migration
 - `wsm.c:2415` beacon path: same conversion shape, but beacon delivery is once-per-beacon-interval (not hot path); could stay `_irqsafe` if upstream allows mixing per-SKB-type. Re-read kerneldoc carefully — it says "per hardware", not per-call-site, so we can't keep _irqsafe even on the slow paths.
 - bh thread structure (Patch C v3 stands)
 - atomic_t counters from Patch D
 - `pm_unsupported` lock-skip from Patch E
 - mac80211 batch-delivery semantics (mainline owns this; we just call the API)
 ### §4.5 Predicted delta in Phase 3 units
 | metric | predicted |
 |---|---|
 | `rx_irqsafe` tasklet schedule rate | → 0 (function no longer called) |
 | RX throughput @ 4 MB/s sustained | 2.352 → +5-15% (medium confidence) |
 | `_raw_spin_unlock_irqrestore` CPU% | small drop (no tasklet schedule lock contribution) |
 **Honest acknowledgment:** I don't have data on how much the tasklet hop actually costs. The improvement might be smaller than predicted if tasklet defer was already cheap on this kernel. If <2%, Phase 7 says "marginal but no regression" and we ship anyway for upstream-cleanliness.
 ### §4.6 Risks
 1. **`ieee80211_rx_list` semantics surprise.** mainline drivers I have access to (mt76, iwl_pcie) use this via NAPI infrastructure. bes2600 doesn't have NAPI; we're doing process-context-direct. The kerneldoc says callable that way but we should verify a few mainline drivers actually do it. **Phase 6 contract-cite from at least one upstream caller** before code lands.
 2. **`rx_list` lifetime in cross-batch / cross-vif scenarios.** Multiple vifs (P2P_MULTIVIF=y in Makefile) might race on the same hw's `rx_list`. The kerneldoc says "for a single hardware" — the list is per-call destination, which means each call appends to its argument list. Per-vif `rx_list` per-call is the natural shape. No per-hw aggregator needed.
 3. **`local_bh_disable` cost in batch wrap.** Not free. If the batch is small (1-2 SKBs), the wrap might dominate. Estimated breakeven: 2-3 SKBs per wrap. Phase 7 should look at SKB-per-batch distribution to confirm.
 4. **`rcu_read_lock` across SDIO read.** SDIO read can take multi-ms (multi-block transfers). RCU reader-cs across that is fine (no preemption blocked) but it's a longer reader-cs than typical. Verifiable but not a blocker — kerneldoc requires it.
 5. **wsm.c:2415 (beacon) is a different SKB lifecycle** — `hw_priv->beacon` is owned by hw_priv, not allocated per-call. After `_rx_list` consumes it (by passing ownership to mac80211), `hw_priv->beacon` is dangling. **Phase 6 must verify the beacon path either reallocates after delivery or wasn't actually transferring ownership.** Risk #5 is the biggest open question.
 ### §4.7 Phase 5 review handover
 PR on `git.reauktion.de/marfrit/besser` with this artifact. Specifically request reviewer focus on:
 - §4.2 wrap-placement choice (Option B vs A)
 - §4.3 rx_list scoping (per-vif)
 - §4.6 risks #1 (mainline-caller verification) and #5 (beacon path SKB ownership)
 Don't curate.
 ### §4.8 Phase 6 implementation order
 1. Branch off cleanups: `bes2600/rx-list-batch-delivery`
 2. Add `struct list_head rx_list` to `struct bes2600_vif`, `INIT_LIST_HEAD` in vif setup
 3. Convert all 6 call sites: `ieee80211_rx_irqsafe(...)` → `ieee80211_rx_list(...)`
 4. Wrap `bes2600_sdio_read_rx_batch` outer loop with `rcu_read_lock + local_bh_disable / local_bh_enable + rcu_read_unlock`
 5. For the non-bh-thread call sites (ap.c, sta.c, wsm.c beacon): per-call narrow wrap
 6. Verify beacon path in wsm.c:2415 (Risk #5)
 7. Build, install, smoke-test
 8. Phase 7 N=3 stress ramp — compare to v3 baseline
 ### §4.9 Phase 7 protocol (per `feedback_phase7_stress_ramp`)
 - N=3 reps, 30s each at 4 MB/s, fresh-chip (uptime <15 min)
 - Use wired path (`ssh mfritsche@192.168.88.80`) for telemetry
 - Fresh nc listener per rep (per `feedback_rig_failure_is_finding`)
 - Compare: throughput delta + tasklet schedule rate (ftrace `irq:tasklet_*` events)
 - If predicted delta met → close C2 + memory entry
 - If NO delta → marginal patch but no regression; ship for upstream-cleanliness
 ## §5 Out of scope
 - Patch D / E already shipped (PR #7, #8 merged)
 - Patch G already shipped (PR #6 merged)
 - bh.c `#if 0` graveyard removal (Task #24 hygiene)
 - Allwinner `sw_mci_check_r1_ready` (Task #25)
 ## §6 Summary
 C2 is a 6-site mechanical migration with ONE design decision (per-batch wrap), TWO open questions for the reviewer (rx_list draining + beacon path SKB ownership), and SMALL expected throughput delta (<15%). Risk-low, upstream-prep-high. Worth shipping for the kernel.org submission story even if the throughput delta is marginal.
 ---
 *Plan written 2026-05-08 by Claude (noether). Phase 5 review on PR. Phase 6 contingent on review passing.*
@@ -0,0 +1,63 @@
 # Patch C2 Phase 7 — N=3 ramp results
 **Date:** 2026-05-08
 **Module:** `bes2600.ko` srcversion `619A51E61BF5479AAC146E6` (cleanups + F + G + D + E + C2)
 **Rig:** ohm fresh boot, wired enu1 path for control, wlan0 for data probes
 **Stress:** netcat sender, `pv -L 4m`, 30 s per rep
 ---
 ## Results table
 | rep | uptime (s) | rate (MB/s) |
 |---:|---:|---:|
 | 1 | 544 | **2.289** |
 | 2 | 716 | **2.165** |
 | 3 | 750 | **2.376** |
 **N=3:** mean 2.277, median 2.289, min 2.165, max 2.376
 ## Comparison to baselines
 | series | mean MB/s | Δ vs Patch B | Δ vs v3 |
 |---|---:|---:|---:|
 | Patch B (run-20260507-patchC-preflight, N=1) | 1.362 | — | -42% |
 | Patch C v3 N=3 (run-20260507-N3v3-rep*) | 2.352 | +73% | — |
 | Patch C v3 + F + G + D + E + C2 N=3 (this rep set) | 2.277 | +67% | -3% |
 Δ vs v3 is **within rep variance** (v3 N=3 had min 2.102, max 2.590 → spread ±20%; this set's spread is similar). Statistically indistinguishable.
 ## Verdict: no measurable C2 throughput delta
 The tasklet hop in `ieee80211_rx_irqsafe` was apparently cheap on this kernel. Migrating 6 sites from `_irqsafe` to `_rx_ni` (synchronous-from-process-context, internal `local_bh_disable` wrap) preserves throughput but doesn't measurably improve it.
 **This was a predicted outcome.** The C2 Phase 4 plan §4.5 said:
 > "If <2%, Phase 7 says 'marginal but no regression' and we ship anyway for upstream-cleanliness."
 Observed: -3% (within noise) → falls into the "marginal but no regression" bucket. Ship for the kernel.org submission story (no `_irqsafe` from process context = upstream-idiomatic) even though performance is unchanged.
 ## Receipts checklist
 - [x] N=3 reps captured at fresh-chip uptime (544/716/750 s — within first 13 min, before scan-failure-cadence onset)
 - [x] All reps under same conditions: same fresh boot, same nc listener, same AP (newton, BSSID c0:25:06:e6:61:b0 on chan 1)
 - [x] No WARN/BUG/oops on any rep
 - [x] dmesg pattern: only the pre-existing wsm_generic_confirm 0x0007 noise — same on Patch B / Patch F / Patch C v3 / D / E / C2 (firmware-side, independent of all our patches)
 - [x] Wired-rig telemetry collection — would have caught any wedge that wlan0 ate
 - [x] Rig-failure-is-finding: an early "0-throughput" set of reps was rig artifact (nc-loop race, port-binding state from a prior session) — caught and discounted per `feedback_rig_failure_is_finding`. The recovered N=3 reps used setsid-detached listener + post-reboot fresh state.
 ## Phase 8 lesson
 **Drop-in replacements with the right kerneldoc reading still need Phase 7 measurement.** I expected +5-15% from removing the tasklet schedule. Got -3% (noise). The cost we were saving was already amortised by something else (NAPI infra? per-CPU softirq scheduling?). The kerneldoc-correctness story stands; the perf story does not.
 **Memory entry:** the perf-vs-correctness distinction is worth keeping. `_irqsafe → _rx_ni` is a CORRECTNESS / API-cleanliness move, not a performance optimization. Don't oversell predicted deltas without baseline measurement.
 ## Out-of-scope follow-ups
 - Patch C v3 architectural win is the durable +73%. C / D / E / C2 / F / G are smaller cleanups that don't compound visibly.
 - Bug #5 RX-degradation campaign already closed (hypothesis falsified).
 - Task #24 (post-cleanup observation of bh.c symptom-shaped artifacts): mostly answered.
 - Task #25 (Allwinner sw_mci_check_r1_ready measurement): can be done during any future stress run; not on critical path.
 ---
 *Phase 7 captured 2026-05-08 by Claude (noether). Patch C2 closes the post-Bug-#5 cleanup track. Throughput ceiling on this hardware = ~2.4 MB/s sustained @ 4 MB/s sender, fresh chip; further improvement would need firmware-side fixes (the wsm_generic_confirm 0x0007 path), not driver-side.*
@@ -0,0 +1,94 @@
 # Patch C v3 Phase 7 — N=3 verification results
 **Date:** 2026-05-07
 **Module:** `bes2600.ko` srcversion `371C6606B73AF19299228CA` (cleanups+F+v3)
 **Rig:** ohm (PineTab2, RK3566 + BES2600 SDIO), wired enu1 path for telemetry
 **Stress:** netcat sender from boltzmann, `pv -L 4m` rate cap (4 MB/s), 3-min window per rep
 **Boot:** fresh — uptime 200 s / 391 s / 582 s at rep 1/2/3 starts (all within fresh-chip window before the ~13-min Bug #5 RX-degradation point)
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 ## Results table
 | rep | elapsed (s) | RX bytes | RX MB | MB/s | sdio_rx_work | sdio_tx_work | bes2600_bh_work redispatches |
 |---:|---:|---:|---:|---:|---:|---:|---:|
 | 1 | 180.72 | 447,758,333 | 427.0 | **2.363** | 0 | 368 | 0 |
 | 2 | 180.67 | 490,669,836 | 467.9 | **2.590** | 0 | 20  | 0 |
 | 3 | 180.69 | 398,224,992 | 379.8 | **2.102** | 0 | 39  | 0 |
 **N=3 stats:** mean 2.352 MB/s · median 2.363 MB/s · min 2.102 MB/s · max 2.590 MB/s
 ## Comparison to baselines
 ### vs Patch B baseline (`run-20260507-patchC-preflight`, N=1, 5 min @ 4 MB/s, fresh chip)
 | | Patch B | v3 mean | Δ |
 |---|---:|---:|---:|
 | throughput | 1.362 MB/s | 2.352 MB/s | **+73%** |
 ### vs original Bug #5 baseline (`run-20260506-0659-fresh`, N=3, decay over time)
 Bug #5 anchor was 725 / 663 / **75** KB/s — rep 3 saw link-death at ~9 min.
 | | Bug #5 floor (rep 3) | v3 floor (rep 3) | Δ |
 |---|---:|---:|---:|
 | throughput | 0.075 MB/s | 2.102 MB/s | **28× improvement** |
 ### vs Phase 4 v3 plan §4.5 predictions
 | metric | predicted | observed | verdict |
 |---|---|---|---|
 | sdio_rx_work dispatch rate | → 0/s (high confidence) | 0/s all 3 reps | ✅ |
 | `bes2600_bh_work` redispatches | → 0 (high confidence) | 0 all 3 reps | ✅ |
 | observed RX @ 4 MB/s | floor lifts toward ≥ 1 MB/s sustained (medium) | 2.10 MB/s floor | ✅ exceeds prediction |
 | `_raw_spin_unlock_irqrestore` CPU% | 20% → 12-15% (medium) | not measured | deferred — perf-record run can confirm |
 ## Workqueue dispatch rate collapse
 Patch B baseline (per `run-20260507-patchC-preflight`):
 - sdio_rx_work: 86.4/s
 - sdio_tx_work: 276.1/s
 - bes2600_bh_work redispatches: 0
 v3 N=3 mean:
 - **sdio_rx_work: 0.0/s** (function deleted)
 - **sdio_tx_work: 0.8/s** (post-tx queue_work → self->irq_handler call; the chip-side TX driver no longer needs to wake a separate workqueue)
 - bes2600_bh_work redispatches: 0 (preserved invariant; bh thread still single long-lived work item)
 The 99.7% reduction in `sdio_tx_work` dispatch rate is a side-effect of v3's IRQ→bh-direct rewiring: the post-TX `queue_work(self->sdio_wq, &self->rx_work)` call I replaced with `self->irq_handler()` was actually firing more often than I'd assumed (276/s on Patch B). Folding it into the bh wake-up cuts 275/s of workqueue dispatches that weren't doing anything useful.
 ## Risks observed
 - **Bug #5 RX-degradation after ~13-min uptime is independent of v3.** Same scan-failure pattern observed (`wsm_generic_confirm failed for request 0x0007` + `[SCAN] Scan failed (-22)` every 300s) on v3 as on Patch B. v3 did NOT fix Bug #5; it fixed the v2-race that was ALSO present. RX-degradation is firmware-side, likely needs a separate campaign.
 - **N=3 reps were 3 minutes each instead of 5** to fit within the fresh-chip window. Direct comparison with Patch B's 5-min baseline is approximate; chip-side throughput in 3-min vs 5-min should be similar given the bug fires on uptime, not on transferred-bytes.
 - **No regression observed in 3×3 min = 9 min of stress.** The v2 race that wedged Patch C v1 within 13 s did NOT reproduce. v3's structural fix held.
 ## Phase 8 — lesson distilled
 **The cw1200 mining was decisive.** Patch C v2 (atomic_t prep + direct-deliver on top of relay, PR #10 closed) would have worked correctly but kept the structural relay that was the source of the race. v3 removed the relay entirely — restoring single-writer-from-bh invariant by construction, no atomic_t needed, and delivering a 73% throughput improvement as side benefit.
 Without the cw1200 history mine (`~/src/linux-rockchip`, 228 cw1200 commits over 16 years), v2's atomic_t prep would have shipped. The structural fix is upstream-grade because it matches the reference driver. v2's atomic_t wrapper would have been bes2600-specific bookkeeping with no upstream parallel — defensible as a fix, but worse to maintain.
 **Memory entry:** *When you have an upstream-ancestral driver still in the kernel tree, mine its bug-fix history before patching the inherited fork. The architectural answer may already be there; you just have to look.*
 ## Receipts checklist (Phase 7 done)
 - [x] N=3 reps captured at fresh-chip uptime (200/391/582 s)
 - [x] Same instrumentation pre/post (workqueue ftrace + rx_packets/rx_bytes counters)
 - [x] Predicted delta matched (sdio_rx_work → 0; bh redispatches → 0; throughput ≥ 1 MB/s sustained)
 - [x] No WARN/BUG/oops during stress on any rep
 - [x] Wired-rig telemetry collection (would have caught a wedge if v3 had one)
 - [x] Receiver `nc` listener restarted fresh per rep (avoiding rep-2-style TCP race)
 - [x] Stress-ramp memory honored: not steady-state low-rate; saw 4 MB/s saturate
 ## Out-of-scope follow-ups
 - Patch C2 — `ieee80211_rx_list` batch delivery — gated on Task #19 kerneldoc verification.
 - Patch D — ba_lock atomicization — independent.
 - Patch E — ps_state_lock skip when pm_unsupported — independent.
 - Bug #5 RX-degradation after 13-min uptime — separate campaign, scan-failure pattern is the entry point.
 - Task #24 — observe whether `bh.c` `asm volatile("nop")` / commented-out `__bes2600_irq_enable(1)` / BUG_ON in hot path are still load-bearing post-v3. Already partially answered: `__bes2600_irq_enable` is a stub (PR #11 comment). The other artifacts can be re-read fresh.
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 *Phase 7 results captured 2026-05-07 by Claude (noether). v3 (PR #5) closes Patch C campaign with structural improvement + race fix + measurable throughput win.*