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authorDylan Reid <dgreid@chromium.org>2013-04-09 05:20:30 +0400
committerTakashi Iwai <tiwai@suse.de>2013-04-09 10:03:22 +0400
commit78daea29f2e5312bce9d7781a5400026b71ed29b (patch)
tree5fd4b8ec656f4cb5cdc2d4360cb08a1351badef5 /sound/pci
parent423970042e0710cdb4f7135f1ed614b956239a91 (diff)
downloadlinux-78daea29f2e5312bce9d7781a5400026b71ed29b.tar.xz
ALSA: hda - Apply codec delay to wallclock.
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>
Diffstat (limited to 'sound/pci')
-rw-r--r--sound/pci/hda/hda_intel.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 735567e86f74..3e6f2c6dc53f 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -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);