From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> [ 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@xxxxxxxxx> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211207173745.15850-7-pierre-louis.bossart@xxxxxxxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Fixes: aa9ff6a4955f ("ASoC: soc-compress: Reposition and add pcm_mutex") Signed-off-by: Yixuan Jiang <yixuanjiang@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # 5.15+ --- 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 b6099d36518f5..6e589708b9338 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2151,7 +2151,10 @@ 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++; -- 2.40.1.521.gf1e218fcd8-goog
