[PATCH 1/1] ASoC: soc-compress: lock pcm_mutex to resolve lockdep error

[이경택]

On Thu, 26 Mar 2020 17:46:07 +0900,
Gyeongtaek Lee wrote:
>Hi,
>
>I'd like to send a patch to fix a problem in soc-compress with DPCM.
>soc_compr_open_fe() and soc_compr_free_fe() call snd_soc_runtime_activate()
>and snd_soc_runtime_deactivate() but don't lock card->pcm_mutex.
>It can cause lockdep error, because snd_soc_runtime_activate/deactivate()
>checks whether pcm_mutex is held using lockdep_assert_held().
>I'd like to send a patch which adds mutex_lock/unlock()
>before and after of the snd_soc_runtime_activate/deactivate() call.
>If there is anything should be changed in my patch or email,
>please let me know it.
>I'll really appreciate it.
>
>Gyeongtaek Lee (1):
>  ASoC: soc-compress: lock pcm_mutex to resolve lockdep error
>
> sound/soc/soc-compress.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>
>base-commit: 76ccd234269bd05debdbc12c96eafe62dd9a6180
>---
>
>snd_soc_runtime_activate() and snd_soc_runtime_deactivate()
>require pcm_mutex lock.
>
>Signed-off-by: Gyeongtaek Lee <gt82.lee at samsung.com>
>---
> sound/soc/soc-compress.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
>index 392a1c5b15d3..42d416ac7e9b 100644
>--- a/sound/soc/soc-compress.c
>+++ b/sound/soc/soc-compress.c
>@@ -207,7 +207,9 @@ static int soc_compr_open_fe(struct snd_compr_stream
*cstream)
> 	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
> 	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
> 
>+	mutex_lock_nested(&fe->pcm_mutex, fe->pcm_subclass);
> 	snd_soc_runtime_activate(fe, stream);
>+	mutex_unlock(&fe->pcm_mutex);
> 
> 	mutex_unlock(&fe->card->mutex);
> 
>@@ -285,7 +287,9 @@ static int soc_compr_free_fe(struct snd_compr_stream
*cstream)
> 	else
> 		stream = SNDRV_PCM_STREAM_CAPTURE;
> 
>+	mutex_lock_nested(&fe->pcm_mutex, fe->pcm_subclass);
> 	snd_soc_runtime_deactivate(fe, stream);
>+	mutex_unlock(&fe->pcm_mutex);
> 
> 	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
> 
>-- 
>2.21.0
>
Hi,

Resending patch with removing tab expansion.

Lee