On start/pause_release/resume, when more than one FE is connected to the same BE, it's possible that the trigger is sent more than once. This is not desirable, we only want to trigger a BE once, which is straightforward to implement with a refcount.
For stop/pause/suspend, the problem is more complicated: the check implemented in snd_soc_dpcm_can_be_free_stop() may fail due to a conceptual deadlock when we trigger the BE before the FE. In this case, the FE states have not yet changed, so there are corner cases where the TRIGGER_STOP is never sent - the dual case of start where multiple triggers might be sent.
This patch suggests an unconditional trigger in all cases, without checking the FE states, using a refcount protected by a spinlock.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- include/sound/soc-dpcm.h | 2 ++ sound/soc/soc-pcm.c | 46 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/include/sound/soc-dpcm.h b/include/sound/soc-dpcm.h index e296a3949b18..6cc751002da7 100644 --- a/include/sound/soc-dpcm.h +++ b/include/sound/soc-dpcm.h @@ -101,6 +101,8 @@ struct snd_soc_dpcm_runtime { enum snd_soc_dpcm_state state;
int trigger_pending; /* trigger cmd + 1 if pending, 0 if not */ + + int be_start; /* refcount protected by dpcm_lock */ };
#define for_each_dpcm_fe(be, stream, _dpcm) \ diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 0717f39d2eec..b2440f2f9bf5 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1534,7 +1534,7 @@ int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream) be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE; goto unwind; } - + be->dpcm[stream].be_start = 0; be->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN; count++; } @@ -2001,6 +2001,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, int ret = 0; unsigned long flags; enum snd_soc_dpcm_state state; + bool do_trigger;
for_each_dpcm_be(fe, stream, dpcm) { struct snd_pcm_substream *be_substream; @@ -2015,6 +2016,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, dev_dbg(be->dev, "ASoC: trigger BE %s cmd %d\n", be->dai_link->name, cmd);
+ do_trigger = false; switch (cmd) { case SNDRV_PCM_TRIGGER_START: spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2025,13 +2027,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, continue; } state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
+ if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2045,13 +2054,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, }
state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
+ if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2065,13 +2081,20 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, }
state = be->dpcm[stream].state; + if (be->dpcm[stream].be_start == 0) + do_trigger = true; + be->dpcm[stream].be_start++; be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
+ if (!do_trigger) + continue; + ret = soc_pcm_trigger(be_substream, cmd); if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2084,9 +2107,15 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if ((be->dpcm[stream].state == SND_SOC_DPCM_STATE_START && + be->dpcm[stream].be_start == 1) || + (be->dpcm[stream].state == SND_SOC_DPCM_STATE_PAUSED && + be->dpcm[stream].be_start == 0)) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue;
spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2098,6 +2127,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2109,9 +2139,12 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if (be->dpcm[stream].be_start == 1) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue;
spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2123,6 +2156,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; } @@ -2134,9 +2168,12 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); continue; } + if (be->dpcm[stream].be_start == 1) + do_trigger = true; + be->dpcm[stream].be_start--; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream)) + if (!do_trigger) continue;
spin_lock_irqsave(&fe->card->dpcm_lock, flags); @@ -2148,6 +2185,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, if (ret) { spin_lock_irqsave(&fe->card->dpcm_lock, flags); be->dpcm[stream].state = state; + be->dpcm[stream].be_start++; spin_unlock_irqrestore(&fe->card->dpcm_lock, flags); goto end; }