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ALSA: hda - Apply codec delay to wallclock.

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For playback add the codec-side delay to the timestamp, for capture
subtract it.  This brings the timestamps in line with the time that
was recently added to the delay reporting.

Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Dylan Reid 2013-04-08 18:20:30 -07:00 committed by Takashi Iwai
parent 423970042e
commit 78daea29f2
1 changed files with 18 additions and 0 deletions
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18
sound/pci/hda/hda_intel.c
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@ -1889,6 +1889,23 @@ static void azx_timecounter_init(struct snd_pcm_substream *substream,
tc->cycle_last = last;
}
static u64 azx_subtract_codec_delay(struct snd_pcm_substream *substream,
u64 nsec)
{
struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];
u64 codec_frames, codec_nsecs;
if (!hinfo->ops.get_delay)
return nsec;
codec_frames = hinfo->ops.get_delay(hinfo, apcm->codec, substream);
codec_nsecs = div_u64(codec_frames * 1000000000LL,
substream->runtime->rate);
return (nsec > codec_nsecs) ? nsec - codec_nsecs : 0;
}
static int azx_get_wallclock_tstamp(struct snd_pcm_substream *substream,
struct timespec *ts)
{
@ -1897,6 +1914,7 @@ static int azx_get_wallclock_tstamp(struct snd_pcm_substream *substream,
nsec = timecounter_read(&azx_dev->azx_tc);
nsec = div_u64(nsec, 3); /* can be optimized */
nsec = azx_subtract_codec_delay(substream, nsec);
*ts = ns_to_timespec(nsec);