From 848aedfdc6ba25ad5652797db9266007773e44dd Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Tue, 7 Dec 2021 11:37:44 -0600 Subject: ASoC: soc-pcm: test refcount before triggering 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 the BE PCM stream lock. Signed-off-by: Pierre-Louis Bossart Reviewed-by: Kai Vehmanen Reviewed-by: Bard Liao Reviewed-by: Ranjani Sridharan Link: https://lore.kernel.org/r/20211207173745.15850-6-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown --- include/sound/soc-dpcm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/sound/soc-dpcm.h') diff --git a/include/sound/soc-dpcm.h b/include/sound/soc-dpcm.h index bc7af90099a8..75b92d883976 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 BE stream pcm lock */ }; #define for_each_dpcm_fe(be, stream, _dpcm) \ -- cgit v1.2.3