ALSA: pcm: add SNDRV_PCM_TRIGGER_DRAIN trigger

Add SNDRV_PCM_TRIGGER_DRAIN trigger for pcm drain.

Some audio devices require notification of drain events
in order to properly drain and shutdown an audio stream.

Signed-off-by: Libin Yang <libin.yang@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 9 insertions, 1 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 095d9572ad2b..ff3abc3b4ff5 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -420,7 +420,8 @@ int snd_pcm_hw_refine(struct snd_pcm_substream *substream,
 
         hw = &substream->runtime->hw;
         if (!params->info) {
-                params->info = hw->info & ~SNDRV_PCM_INFO_FIFO_IN_FRAMES;
+                params->info = hw->info & ~(SNDRV_PCM_INFO_FIFO_IN_FRAMES |
+                                            SNDRV_PCM_INFO_DRAIN_TRIGGER);
                 if (!hw_support_mmap(substream))
                         params->info &= ~(SNDRV_PCM_INFO_MMAP |
                                           SNDRV_PCM_INFO_MMAP_VALID);
@@ -1566,6 +1567,13 @@ static int snd_pcm_do_drain_init(struct snd_pcm_substream *substream, int state)
                         snd_pcm_post_stop(substream, new_state);
                 }
         }
+
+        if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
+            runtime->trigger_master == substream &&
+            (runtime->hw.info & SNDRV_PCM_INFO_DRAIN_TRIGGER))
+                return substream->ops->trigger(substream,
+                                               SNDRV_PCM_TRIGGER_DRAIN);
+
         return 0;
 }