test0r
aff632ea64
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>
84 lines
2.6 KiB
C
84 lines
2.6 KiB
C
/*
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* Scan interface for BES2600 mac80211 drivers
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*
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* Copyright (c) 2010, Bestechnic
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* Author:
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef SCAN_H_INCLUDED
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#define SCAN_H_INCLUDED
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#include <linux/semaphore.h>
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#include "wsm.h"
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/* external */ struct sk_buff;
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/* external */ struct cfg80211_scan_request;
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/* external */ struct ieee80211_channel;
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/* external */ struct ieee80211_hw;
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/* external */ struct work_struct;
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struct bes2600_scan {
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struct semaphore lock;
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struct work_struct work;
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#ifdef ROAM_OFFLOAD
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struct work_struct swork; /* scheduled scan work */
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struct cfg80211_sched_scan_request *sched_req;
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#endif /*ROAM_OFFLOAD*/
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struct delayed_work timeout;
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struct cfg80211_scan_request *req;
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struct ieee80211_channel **begin;
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struct ieee80211_channel **curr;
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struct ieee80211_channel **end;
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struct wsm_ssid ssids[WSM_SCAN_MAX_NUM_OF_SSIDS];
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int output_power;
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int n_ssids;
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int status;
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atomic_t in_progress;
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/* Direct probe requests workaround */
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struct delayed_work probe_work;
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int direct_probe;
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u8 if_id;
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/*
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* Track consecutive firmware-side WSM scan rejections so we can
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* back off briefly instead of re-issuing the same scan on every
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* mac80211 background-scan tick. Firmware returns WSM status != 0
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* for a handful of transient conditions (BT A2DP active in non-
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* FDD coex, firmware-internal busy windows) and keeps rejecting
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* until the state clears; retrying at full cadence just floods
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* dmesg.
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*/
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unsigned int reject_count;
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unsigned long backoff_until;
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};
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int bes2600_hw_scan(struct ieee80211_hw *hw,
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struct ieee80211_vif *vif,
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struct ieee80211_scan_request *hw_req);
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#ifdef ROAM_OFFLOAD
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int bes2600_hw_sched_scan_start(struct ieee80211_hw *hw,
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struct ieee80211_vif *vif,
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struct cfg80211_sched_scan_request *req,
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struct ieee80211_sched_scan_ies *ies);
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void bes2600_hw_sched_scan_stop(struct bes2600_common *priv);
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void bes2600_sched_scan_work(struct work_struct *work);
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#endif /*ROAM_OFFLOAD*/
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void bes2600_scan_work(struct work_struct *work);
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void bes2600_scan_timeout(struct work_struct *work);
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void bes2600_scan_complete_cb(struct bes2600_common *priv,
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struct wsm_scan_complete *arg);
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void bes2600_cancel_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
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/* ******************************************************************** */
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/* Raw probe requests TX workaround */
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void bes2600_probe_work(struct work_struct *work);
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#ifdef CONFIG_BES2600_TESTMODE
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/* Advance Scan Timer */
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void bes2600_advance_scan_timeout(struct work_struct *work);
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#endif
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#endif
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