Merge tag 'for-f2fs-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk...

[cascardo/linux.git] / sound / usb / pcm.c

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 0d8aba5..b4ef410 100644 (file)
--- 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;