[alsa-devel] [PATCH 1/2] ALSA: usb-audio: ignore delay calculation for capture stream

[Takashi Iwai]

It doesn't make sense to calculate the delay for capture streams in
the current implementation.  It's always zero, so we should skip the
computation in snd_usb_pcm_pointer() in the case of capture.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/usb/pcm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index e919c2e..8e1d5e0 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -75,7 +75,8 @@ static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream
 		return SNDRV_PCM_POS_XRUN;
 	spin_lock(&subs->lock);
 	hwptr_done = subs->hwptr_done;
-	substream->runtime->delay = snd_usb_pcm_delay(subs,
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		substream->runtime->delay = snd_usb_pcm_delay(subs,
 						substream->runtime->rate);
 	spin_unlock(&subs->lock);
 	return hwptr_done / (substream->runtime->frame_bits >> 3);
-- 
1.8.0