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| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2015-02-06 22:55:51 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2015-02-09 16:01:53 +0100 |
| commit | 2b79d7a6bf341ebeffb85fc2b3577d0cfa810c49 (patch) | |
| tree | 164985dd74d92ed3563be5d52f656e1d7dd9444f /sound/core | |
| parent | ALSA: pcm: don't override timestamp unconditionally (diff) | |
| download | linux-2b79d7a6bf341ebeffb85fc2b3577d0cfa810c49.tar.xz linux-2b79d7a6bf341ebeffb85fc2b3577d0cfa810c49.zip | |
ALSA: pcm: allow for trigger_tstamp snapshot in .trigger
Don't use generic snapshot of trigger_tstamp if low-level driver or
hardware can get a more precise value for better audio/system time
synchronization.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm_native.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 4ecd35fbfe3f..b03a638b420c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -810,7 +810,8 @@ static void snd_pcm_trigger_tstamp(struct snd_pcm_substream *substream) if (runtime->trigger_master == NULL) return; if (runtime->trigger_master == substream) { - snd_pcm_gettime(runtime, &runtime->trigger_tstamp); + if (!runtime->trigger_tstamp_latched) + snd_pcm_gettime(runtime, &runtime->trigger_tstamp); } else { snd_pcm_trigger_tstamp(runtime->trigger_master); runtime->trigger_tstamp = runtime->trigger_master->runtime->trigger_tstamp; @@ -979,6 +980,7 @@ static int snd_pcm_pre_start(struct snd_pcm_substream *substream, int state) if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !snd_pcm_playback_data(substream)) return -EPIPE; + runtime->trigger_tstamp_latched = false; runtime->trigger_master = substream; return 0; } |