ASoC: soc-pcm: improve BE transition for PAUSE_RELEASE

Commit 3aa1e96a2b95 ("ASoC: soc-pcm: fix BE handling of PAUSE_RELEASE")
did not modify the existing logic and kept the same logic for the following
transition

    play FE1    -> BE state is START
    pause FE1   -> BE state is PAUSED
    play FE2    -> BE state is START
    stop FE2    -> BE state is STOP <<< !!
    release FE1 -> BE state is START
    stop FE1    -> BE state is STOP

At the time it was identified by reviewers that a better solution
might consist in

    play FE1    -> BE state is START
    pause FE1   -> BE state is PAUSED
    play FE2    -> BE state is START
    stop FE2    -> BE state is PAUSE <<< !!
    release FE1 -> BE state is START
    stop FE1    -> BE state is STOP

This patch suggest a transition to PAUSE when all the 'active' streams
are paused. This would allow for a more consistent resource management
for platforms where PAUSE and STOP are handled differently.

To track the special case of an FE going from PAUSE_PUSH to STOP, we
add a state variable for each FE context. This 'fe_pause' boolean is
set on PAUSE_PUSH and cleared on either PAUSE_RELEASE and STOP
triggers.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220406190056.233481-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/include/sound/soc-dpcm.h b/include/sound/soc-dpcm.h
index 75b92d8..5b689c6 100644 (file)
--- a/include/sound/soc-dpcm.h
+++ b/include/sound/soc-dpcm.h
@@ -103,6 +103,8 @@ struct snd_soc_dpcm_runtime {
        int trigger_pending; /* trigger cmd + 1 if pending, 0 if not */
 
        int be_start; /* refcount protected by BE stream pcm lock */
+       int be_pause; /* refcount protected by BE stream pcm lock */
+       bool fe_pause; /* used to track STOP after PAUSE */
 };
 
 #define for_each_dpcm_fe(be, stream, _dpcm)                            \

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index 11c9853..e8700dd 100644 (file)
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -2090,6 +2090,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                               int cmd)
 {
        struct snd_soc_pcm_runtime *be;
+       bool pause_stop_transition;
        struct snd_soc_dpcm *dpcm;
        unsigned long flags;
        int ret = 0;
@@ -2148,10 +2149,12 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                        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;
 
+                       fe->dpcm[stream].fe_pause = false;
+                       be->dpcm[stream].be_pause--;
+
                        be->dpcm[stream].be_start++;
                        if (be->dpcm[stream].be_start != 1)
                                goto next;
@@ -2175,14 +2178,33 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                        if (be->dpcm[stream].be_start != 0)
                                goto next;
 
-                       ret = soc_pcm_trigger(be_substream, cmd);
+                       pause_stop_transition = false;
+                       if (fe->dpcm[stream].fe_pause) {
+                               pause_stop_transition = true;
+                               fe->dpcm[stream].fe_pause = false;
+                               be->dpcm[stream].be_pause--;
+                       }
+
+                       if (be->dpcm[stream].be_pause != 0)
+                               ret = soc_pcm_trigger(be_substream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
+                       else
+                               ret = soc_pcm_trigger(be_substream, SNDRV_PCM_TRIGGER_STOP);
+
                        if (ret) {
                                if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_START)
                                        be->dpcm[stream].be_start++;
+                               if (pause_stop_transition) {
+                                       fe->dpcm[stream].fe_pause = true;
+                                       be->dpcm[stream].be_pause++;
+                               }
                                goto next;
                        }
 
-                       be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
+                       if (be->dpcm[stream].be_pause != 0)
+                               be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
+                       else
+                               be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
+
                        break;
                case SNDRV_PCM_TRIGGER_SUSPEND:
                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
@@ -2204,6 +2226,9 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
                                goto next;
 
+                       fe->dpcm[stream].fe_pause = true;
+                       be->dpcm[stream].be_pause++;
+
                        be->dpcm[stream].be_start--;
                        if (be->dpcm[stream].be_start != 0)
                                goto next;