fsl_xcvr_activate_ctl() has 
lockdep_assert_held(&card->snd_card->controls_rwsem),
but fsl_xcvr_mode_put() calls it without acquiring this lock.

Other callers of fsl_xcvr_activate_ctl() in fsl_xcvr_startup() and
fsl_xcvr_shutdown() properly acquire the lock with down_read()/up_read().

Add the missing down_read()/up_read() calls around fsl_xcvr_activate_ctl()
in fsl_xcvr_mode_put() to fix the lockdep assertion and prevent potential
race conditions when multiple userspace threads access the control.

Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
---
 sound/soc/fsl/fsl_xcvr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/fsl/fsl_xcvr.c b/sound/soc/fsl/fsl_xcvr.c
index a268fb81a2f8..0b9dd64b9a82 100644
--- a/sound/soc/fsl/fsl_xcvr.c
+++ b/sound/soc/fsl/fsl_xcvr.c
@@ -223,10 +223,13 @@ static int fsl_xcvr_mode_put(struct snd_kcontrol *kcontrol,
 
 	xcvr->mode = snd_soc_enum_item_to_val(e, item[0]);
 
+	down_read(&card->snd_card->controls_rwsem);
 	fsl_xcvr_activate_ctl(dai, fsl_xcvr_arc_mode_kctl.name,
 			      (xcvr->mode == FSL_XCVR_MODE_ARC));
 	fsl_xcvr_activate_ctl(dai, fsl_xcvr_earc_capds_kctl.name,
 			      (xcvr->mode == FSL_XCVR_MODE_EARC));
+	up_read(&card->snd_card->controls_rwsem);
+
 	/* Allow playback for SPDIF only */
 	rtd = snd_soc_get_pcm_runtime(card, card->dai_link);
 	rtd->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count =
-- 
2.34.1

On Mon, 02 Feb 2026 17:41:12 +0000, Ziyi Guo wrote:
> fsl_xcvr_activate_ctl() has
> lockdep_assert_held(&card->snd_card->controls_rwsem),
> but fsl_xcvr_mode_put() calls it without acquiring this lock.
> 
> Other callers of fsl_xcvr_activate_ctl() in fsl_xcvr_startup() and
> fsl_xcvr_shutdown() properly acquire the lock with down_read()/up_read().
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl_xcvr: fix missing lock in fsl_xcvr_mode_put()
      commit: f514248727606b9087bc38a284ff686e0093abf1

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark