The bes2600 driver is a fork of the upstream cw1200 driver
(drivers/net/wireless/st/cw1200/, ST-Ericsson, Dmitry Tarnyagin
2010-2011). The fork's file headers have three GPL-compliance issues:
1. NO SPDX-License-Identifier on any of 48 source files (cw1200
mainline has them on all 25). kernel.org-mandated since 2017.
2. Original "Copyright (c) 2010, ST-Ericsson" lines stripped from
all files inherited from cw1200, replaced with
"Copyright (c) 2010, Bestechnic" — factually impossible
(Bestechnic did not author the 2010 work) and a GPL-2.0 §1
attribution-preservation violation.
3. The "GPL version 2 as published by the Free Software Foundation"
boilerplate paragraph is redundant alongside SPDX and is the
legacy form modern kernel sources have replaced.
This patch corrects all three for the 48 .c/.h files in bes2600/:
- Adds `// SPDX-License-Identifier: GPL-2.0-only` (or `/* ... */`
for headers) as line 1 of every file.
- Restores `Copyright (c) 2010, ST-Ericsson` + `Author: Dmitry
Tarnyagin <dmitry.tarnyagin@lockless.no>` as the FIRST copyright
chain entry on all 22 files derived from cw1200 (bh.{c,h},
debug.{c,h}, fwio.{c,h}, hwio.{c,h}, main.c, pm.{c,h},
queue.{c,h}, scan.{c,h}, sta.{c,h}, txrx.{c,h}, wsm.{c,h}).
- Keeps `Copyright (c) 2022, Bestechnic (Beijing) Co., Ltd.` as
the SECOND chain entry where Bestechnic genuinely contributed.
- Notes "Derived from cw1200_sdio.c" + ST-Ericsson copyright on
bes2600_sdio.c (heavy derivation, not a literal rename).
- Notes "Replaces hwbus.h from cw1200/" + ST-Ericsson copyright
on sbus.h.
- Preserves the prism54/islsm authorship chain on main.c and
bes2600.h (Michael Wu 2006 + Jean-Baptiste Note 2004-2006).
- Drops the GPL-2.0 boilerplate paragraph in favour of SPDX.
No code changes — only file-header comment blocks. Module build is
unaffected (verified by header-only diff scope).
This is a prerequisite for any kernel.org submission attempt. The
existing MODULE_LICENSE("GPL") + MODULE_AUTHOR(Tarnyagin@stericsson.com)
declarations were already present and are unchanged here; the
mismatch between MODULE_AUTHOR and the (since-corrected) per-file
copyrights is now resolved.
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>
test0r
Julian