ALSA: Add extra delay count in PCM
Added runtime->delay field to adjust the delayed samples for snd_pcm_delay().
Typically a hardware FIFO length is stored in this field, so that the
extra delay between hwptr and applptr can be computed.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index c172968..267effd 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -270,6 +270,7 @@
snd_pcm_uframes_t hw_ptr_base; /* Position at buffer restart */
snd_pcm_uframes_t hw_ptr_interrupt; /* Position at interrupt time */
unsigned long hw_ptr_jiffies; /* Time when hw_ptr is updated */
+ snd_pcm_sframes_t delay; /* extra delay; typically FIFO size */
/* -- HW params -- */
snd_pcm_access_t access; /* access mode */
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index fc6f98e..cb769d4 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -587,14 +587,15 @@
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
status->avail = snd_pcm_playback_avail(runtime);
if (runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
- runtime->status->state == SNDRV_PCM_STATE_DRAINING)
+ runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
status->delay = runtime->buffer_size - status->avail;
- else
+ status->delay += runtime->delay;
+ } else
status->delay = 0;
} else {
status->avail = snd_pcm_capture_avail(runtime);
if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
- status->delay = status->avail;
+ status->delay = status->avail + runtime->delay;
else
status->delay = 0;
}
@@ -2404,6 +2405,7 @@
n = snd_pcm_playback_hw_avail(runtime);
else
n = snd_pcm_capture_avail(runtime);
+ n += runtime->delay;
break;
case SNDRV_PCM_STATE_XRUN:
err = -EPIPE;