linux-kernel - [PATCH v2] regmap: slimbus: fix bus_context pointer in regmap init calls

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Message-ID: <20251022201013.1740211-1-alexey.klimov@linaro.org>
Date: Wed, 22 Oct 2025 21:10:12 +0100
From: Alexey Klimov <alexey.klimov@...aro.org>
To: broonie@...nel.org,
	gregkh@...uxfoundation.org,
	srini@...nel.org
Cc: rafael@...nel.org,
	dakr@...nel.org,
	make24@...as.ac.cn,
	steev@...i.org,
	dmitry.baryshkov@....qualcomm.com,
	linux-kernel@...r.kernel.org,
	linux-sound@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	abel.vesa@...aro.org,
	stable@...r.kernel.org
Subject: [PATCH v2] regmap: slimbus: fix bus_context pointer in regmap init calls

Commit 4e65bda8273c ("ASoC: wcd934x: fix error handling in
wcd934x_codec_parse_data()") revealed the problem in the slimbus regmap.
That commit breaks audio playback, for instance, on sdm845 Thundercomm
Dragonboard 845c board:

 Unable to handle kernel paging request at virtual address ffff8000847cbad4
 ...
 CPU: 5 UID: 0 PID: 776 Comm: aplay Not tainted 6.18.0-rc1-00028-g7ea30958b305 #11 PREEMPT
 Hardware name: Thundercomm Dragonboard 845c (DT)
 ...
 Call trace:
  slim_xfer_msg+0x24/0x1ac [slimbus] (P)
  slim_read+0x48/0x74 [slimbus]
  regmap_slimbus_read+0x18/0x24 [regmap_slimbus]
  _regmap_raw_read+0xe8/0x174
  _regmap_bus_read+0x44/0x80
  _regmap_read+0x60/0xd8
  _regmap_update_bits+0xf4/0x140
  _regmap_select_page+0xa8/0x124
  _regmap_raw_write_impl+0x3b8/0x65c
  _regmap_bus_raw_write+0x60/0x80
  _regmap_write+0x58/0xc0
  regmap_write+0x4c/0x80
  wcd934x_hw_params+0x494/0x8b8 [snd_soc_wcd934x]
  snd_soc_dai_hw_params+0x3c/0x7c [snd_soc_core]
  __soc_pcm_hw_params+0x22c/0x634 [snd_soc_core]
  dpcm_be_dai_hw_params+0x1d4/0x38c [snd_soc_core]
  dpcm_fe_dai_hw_params+0x9c/0x17c [snd_soc_core]
  snd_pcm_hw_params+0x124/0x464 [snd_pcm]
  snd_pcm_common_ioctl+0x110c/0x1820 [snd_pcm]
  snd_pcm_ioctl+0x34/0x4c [snd_pcm]
  __arm64_sys_ioctl+0xac/0x104
  invoke_syscall+0x48/0x104
  el0_svc_common.constprop.0+0x40/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x34/0xec
  el0t_64_sync_handler+0xa0/0xf0
  el0t_64_sync+0x198/0x19c

The __devm_regmap_init_slimbus() started to be used instead of
__regmap_init_slimbus() after the commit mentioned above and turns out
the incorrect bus_context pointer (3rd argument) was used in
__devm_regmap_init_slimbus(). It should be just "slimbus" (which is equal
to &slimbus->dev). Correct it. The wcd934x codec seems to be the only or
the first user of devm_regmap_init_slimbus() but we should fix it till
the point where __devm_regmap_init_slimbus() was introduced therefore
two "Fixes" tags.

While at this, also correct the same argument in __regmap_init_slimbus().

Fixes: 4e65bda8273c ("ASoC: wcd934x: fix error handling in wcd934x_codec_parse_data()")
Fixes: 7d6f7fb053ad ("regmap: add SLIMbus support")
Cc: stable@...r.kernel.org
Cc: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
Cc: Ma Ke <make24@...as.ac.cn>
Cc: Steev Klimaszewski <steev@...i.org>
Cc: Srinivas Kandagatla <srini@...nel.org>
Reviewed-by: Abel Vesa <abel.vesa@...aro.org>
Signed-off-by: Alexey Klimov <alexey.klimov@...aro.org>
---

The patch/fix is for the current 6.18 development cycle
since it fixes the regression introduced in 6.18.0-rc1.

Changes in v2:
 - &slimbus->dev replaced with just "slimbus", no functional change
 (as suggested by Dmitry);
 - the same argument in __regmap_init_slimbus() was replaced with
 "slimbus" (as suggested by Dmitry);
 - reduced the backtrace log in the commit message (as suggested by Mark);
 - corrected subject/title, few typos, added mention of non-managed init
 func change, rephrased smth;
 - added Reviewed-by tag from Abel.

Prev version: https://lore.kernel.org/linux-sound/20251020015557.1127542-1-alexey.klimov@linaro.org/

 drivers/base/regmap/regmap-slimbus.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/base/regmap/regmap-slimbus.c b/drivers/base/regmap/regmap-slimbus.c
index 54eb7d227cf4..e523fae73004 100644
--- a/drivers/base/regmap/regmap-slimbus.c
+++ b/drivers/base/regmap/regmap-slimbus.c
@@ -48,8 +48,7 @@ struct regmap *__regmap_init_slimbus(struct slim_device *slimbus,
 	if (IS_ERR(bus))
 		return ERR_CAST(bus);

-	return __regmap_init(&slimbus->dev, bus, &slimbus->dev, config,
-			     lock_key, lock_name);
+	return __regmap_init(&slimbus->dev, bus, slimbus, config, lock_key, lock_name);
 }
 EXPORT_SYMBOL_GPL(__regmap_init_slimbus);

@@ -63,8 +62,7 @@ struct regmap *__devm_regmap_init_slimbus(struct slim_device *slimbus,
 	if (IS_ERR(bus))
 		return ERR_CAST(bus);

-	return __devm_regmap_init(&slimbus->dev, bus, &slimbus, config,
-				  lock_key, lock_name);
+	return __devm_regmap_init(&slimbus->dev, bus, slimbus, config, lock_key, lock_name);
 }
 EXPORT_SYMBOL_GPL(__devm_regmap_init_slimbus);

-- 
2.47.3