fleet/ohm: import Patch I (5GHz scan filter) + arm64 SCS build-fix

Patch I closes besser#1 — the wsm_generic_confirm 0x0007 dmesg storm.
One-line guard in bes2600_hw_scan() refuses the 5 GHz iteration of
mac80211's per-band hw_scan loop with -EOPNOTSUPP, so the firmware
never sees the scan request that would be rejected with status 2 →
-EINVAL cascade.  Phase 7 verified 2026-05-18 on ohm running pkgrel=2:
Pattern A 14.3/h → 0/h over 30-min window, no WARN/BUG, single-band
2.4 GHz scans still return BSSes cleanly.

Two flavors imported (scan-filter-5ghz and scan-filter-5ghz-danctnix)
matching the convention of other bes2600 series — the code path
doesn't touch timer APIs so the two are byte-identical for now;
flavor separation is kept to preserve consistency in ohm.yaml.

The arm64 scs-arm-neon-build-fix series is a build-environment
workaround: GCC 15.2.1 strictly validates that -fsanitize=shadow-
call-stack requires -ffixed-x18, and arm_neon.h's #pragma target/
push/pop blocks lose x18 fixing inside the wrapped section.  The
Makefile tweak re-adds -ffixed-x18 explicitly for xor-neon.o.  It's
a no-op when SCS is off (current pkgrel=2 ohm config) and unblocks
SCS=y once GCC upstream is fixed.

ohm.yaml gains a CONFIG_SHADOW_CALL_STACK=n config override with a
pointer to besser#20 (the re-enable tracking issue) so future
manifest-driven kconfig generation honors the workaround without
silently dropping it.

Source-of-truth commit for Patch I:
  marfrit/bes2600-dkms branch bes2600/scan-filter-5ghz sha 093a503
PKGBUILD-side (already deployed to ohm via pkgrel=2):
  marfrit/besser branch claude-noether-14 sha ae175f9

Refs: besser#1 (closed), besser#20, kernel-agent#5
This commit is contained in:
2026-05-18 15:25:37 +02:00
parent 96af34d775
commit 4c80458d1f
4 changed files with 236 additions and 0 deletions
@@ -0,0 +1,91 @@
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] 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
@@ -0,0 +1,91 @@
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] 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