diff options
| -rw-r--r-- | sound/usb/card.h | 2 | ||||
| -rw-r--r-- | sound/usb/pcm.c | 9 |
2 files changed, 11 insertions, 0 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h index 97acb906acc..ef580b43f1e 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -153,6 +153,8 @@ struct snd_usb_substream { int channel; int byte_idx; } dsd_dop; + + bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */ }; struct snd_usb_stream { 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; |