diff options
Diffstat (limited to 'sound/usb/pcm.c')
| -rw-r--r-- | sound/usb/pcm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 0d8aba5fe1a..b4ef410e5a9 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1464,6 +1464,14 @@ static void prepare_playback_urb(struct snd_usb_substream *subs, subs->last_frame_number = usb_get_current_frame_number(subs->dev); subs->last_frame_number &= 0xFF; /* keep 8 LSBs */ + if (subs->trigger_tstamp_pending_update) { + /* this is the first actual URB submitted, + * update trigger timestamp to reflect actual start time + */ + snd_pcm_gettime(runtime, &runtime->trigger_tstamp); + subs->trigger_tstamp_pending_update = false; + } + spin_unlock_irqrestore(&subs->lock, flags); urb->transfer_buffer_length = bytes; if (period_elapsed) @@ -1550,6 +1558,7 @@ static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substrea switch (cmd) { case SNDRV_PCM_TRIGGER_START: + subs->trigger_tstamp_pending_update = true; case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: subs->data_endpoint->prepare_data_urb = prepare_playback_urb; subs->data_endpoint->retire_data_urb = retire_playback_urb; |