If panic_on_warn=1 is added in bootargs and compress offload playback with DPCM is started, kernel panic would be occurred because rtd->card->pcm_mutex isn't held in soc_compr_open_fe() and soc_compr_free_fe() and it generates lockdep warning in the following code.

void snd_soc_runtime_action(struct snd_soc_pcm_runtime *rtd, int stream, int action) { struct snd_soc_dai *dai; int i;

lockdep_assert_held(&rtd->card->pcm_mutex);

To prevent lockdep warning but minimize side effect by adding mutex, pcm_mutex is held just before snd_soc_runtime_activate() and snd_soc_runtime_deactivate() and is released right after them.

Signed-off-by: Gyeongtaek Lee gt82.lee@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 246a5e32e22a..b4810266f5e5 100644 --- a/sound/soc/soc-compress.c +++ b/sound/soc/soc-compress.c @@ -153,7 +153,9 @@ 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->card->pcm_mutex, fe->card->pcm_subclass); snd_soc_runtime_activate(fe, stream); + mutex_unlock(&fe->card->pcm_mutex);

mutex_unlock(&fe->card->mutex);

@@ -181,7 +183,9 @@ static int soc_compr_free_fe(struct snd_compr_stream *cstream)

mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);

+ mutex_lock_nested(&fe->card->pcm_mutex, fe->card->pcm_subclass); snd_soc_runtime_deactivate(fe, stream); + mutex_unlock(&fe->card->pcm_mutex);

fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;

base-commit: e49d033bddf5b565044e2abe4241353959bc9120