From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
[ Upstream commit 3aa1e96a2b95e2ece198f8dd01e96818971b84df ]
A BE connected to more than one FE, e.g. in a mixer case, can go through the following transitions.
play FE1 -> BE state is START pause FE1 -> BE state is PAUSED play FE2 -> BE state is START stop FE2 -> BE state is STOP (see note [1] below) release FE1 -> BE state is START stop FE1 -> BE state is STOP
play FE1 -> BE state is START pause FE1 -> BE state is PAUSED play FE2 -> BE state is START release FE1 -> BE state is START stop FE2 -> BE state is START stop FE1 -> BE state is STOP
play FE1 -> BE state is START play FE2 -> BE state is START (no change) pause FE1 -> BE state is START (no change) pause FE2 -> BE state is PAUSED release FE1 -> BE state is START release FE2 -> BE state is START (no change) stop FE1 -> BE state is START (no change) stop FE2 -> BE state is STOP
The existing code for PAUSE_RELEASE only allows for the case where the BE is paused, which clearly would not work in the sequences above.
Extend the allowed states to restart the BE when PAUSE_RELEASE is received, and increase the refcount if the BE is already in START.
[1] the existing logic does not move the BE state back to PAUSED when the FE2 is stopped. This patch does not change the logic; it would be painful to keep a history of changes on the FE side, the state machine is already rather complicated with transitions based on the last BE state and the trigger type.
Reported-by: Bard Liao bard.liao@intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Kai Vehmanen kai.vehmanen@linux.intel.com Reviewed-by: Bard Liao yung-chuan.liao@linux.intel.com Reviewed-by: Ranjani Sridharan ranjani.sridharan@linux.intel.com Link: https://lore.kernel.org/r/20211207173745.15850-7-pierre-louis.bossart@linux.... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- sound/soc/soc-pcm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 83977a715a61d..7f96b7d4b3dac 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2155,7 +2155,10 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream, be->dpcm[stream].state = SND_SOC_DPCM_STATE_START; break; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: - if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) + if (!be->dpcm[stream].be_start && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED)) goto next;
be->dpcm[stream].be_start++;