There is no need for a DPCM-specific lock at the card level, we can use the FE-specific PCM lock instead. In addition, these PCM locks will rely on either a spin-lock or a mutex depending on atomicity.
Since the FE PCM lock is already taken during the trigger, new _locked versions of the helpers snd_soc_dpcm_can_be_free_stop() and snd_soc_dpcm_check_state() are introduced. Without these changes a conceptual deadlock happens on TRIGGER_STOP.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- include/sound/soc.h | 2 -- sound/soc/soc-core.c | 1 - sound/soc/soc-pcm.c | 55 +++++++++++++++++++++++++++++++++++--------- 3 files changed, 44 insertions(+), 14 deletions(-)
diff --git a/include/sound/soc.h b/include/sound/soc.h index 8e6dd8a257c5..5872a8864f3b 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -893,8 +893,6 @@ struct snd_soc_card { struct mutex pcm_mutex; enum snd_soc_pcm_subclass pcm_subclass;
- spinlock_t dpcm_lock; - int (*probe)(struct snd_soc_card *card); int (*late_probe)(struct snd_soc_card *card); int (*remove)(struct snd_soc_card *card); diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 80ca260595fd..b029e07ad1e1 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2339,7 +2339,6 @@ int snd_soc_register_card(struct snd_soc_card *card) mutex_init(&card->mutex); mutex_init(&card->dapm_mutex); mutex_init(&card->pcm_mutex); - spin_lock_init(&card->dpcm_lock);
return snd_soc_bind_card(card); } diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index f22bbf95319d..797f0d114c83 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -31,13 +31,13 @@
void snd_soc_dpcm_fe_lock_irq(struct snd_soc_pcm_runtime *fe, int stream) { - spin_lock_irq(&fe->card->dpcm_lock); + snd_pcm_stream_lock_irq(snd_soc_dpcm_get_substream(fe, stream)); } EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_lock_irq);
void snd_soc_dpcm_fe_unlock_irq(struct snd_soc_pcm_runtime *fe, int stream) { - spin_unlock_irq(&fe->card->dpcm_lock); + snd_pcm_stream_unlock_irq(snd_soc_dpcm_get_substream(fe, stream)); } EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_unlock_irq);
@@ -45,6 +45,9 @@ EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_unlock_irq); static int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe, struct snd_soc_pcm_runtime *be, int stream);
+static int snd_soc_dpcm_can_be_free_stop_locked(struct snd_soc_pcm_runtime *fe, + struct snd_soc_pcm_runtime *be, int stream); + /* can this BE perform a hw_params() */ static int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe, struct snd_soc_pcm_runtime *be, int stream); @@ -2101,7 +2104,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream)) continue;
ret = soc_pcm_trigger(be_substream, cmd); @@ -2114,7 +2117,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream)) continue;
ret = soc_pcm_trigger(be_substream, cmd); @@ -2127,7 +2130,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream)) continue;
ret = soc_pcm_trigger(be_substream, cmd); @@ -2873,18 +2876,17 @@ struct snd_pcm_substream * } EXPORT_SYMBOL_GPL(snd_soc_dpcm_get_substream);
-static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe, - struct snd_soc_pcm_runtime *be, - int stream, - const enum snd_soc_dpcm_state *states, - int num_states) +static int snd_soc_dpcm_check_state_locked(struct snd_soc_pcm_runtime *fe, + struct snd_soc_pcm_runtime *be, + int stream, + const enum snd_soc_dpcm_state *states, + int num_states) { struct snd_soc_dpcm *dpcm; int state; int ret = 1; int i;
- snd_soc_dpcm_fe_lock_irq(fe, stream); for_each_dpcm_fe(be, stream, dpcm) {
if (dpcm->fe == fe) @@ -2898,12 +2900,43 @@ static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe, } } } + + /* it's safe to do this BE DAI */ + return ret; +} + +static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe, + struct snd_soc_pcm_runtime *be, + int stream, + const enum snd_soc_dpcm_state *states, + int num_states) +{ + int ret; + + snd_soc_dpcm_fe_lock_irq(fe, stream); + ret = snd_soc_dpcm_check_state_locked(fe, be, stream, states, num_states); snd_soc_dpcm_fe_unlock_irq(fe, stream);
/* it's safe to do this BE DAI */ return ret; }
+/* + * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE + * are not running, paused or suspended for the specified stream direction. + */ +static int snd_soc_dpcm_can_be_free_stop_locked(struct snd_soc_pcm_runtime *fe, + struct snd_soc_pcm_runtime *be, int stream) +{ + const enum snd_soc_dpcm_state state[] = { + SND_SOC_DPCM_STATE_START, + SND_SOC_DPCM_STATE_PAUSED, + SND_SOC_DPCM_STATE_SUSPEND, + }; + + return snd_soc_dpcm_check_state_locked(fe, be, stream, state, ARRAY_SIZE(state)); +} + /* * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE * are not running, paused or suspended for the specified stream direction.