diff options
| -rw-r--r-- | sound/usb/pcm.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 8e1d5e0..7c64b95 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -46,6 +46,9 @@ snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs, int frame_diff; int est_delay; + if (!subs->last_delay) + return 0; /* short path */ + current_frame_number = usb_get_current_frame_number(subs->dev); /* * HCD implementations use different widths, use lower 8 bits. @@ -1195,6 +1198,9 @@ static void retire_playback_urb(struct snd_usb_substream *subs, return; spin_lock_irqsave(&subs->lock, flags); + if (!subs->last_delay) + goto out; /* short path */ + est_delay = snd_usb_pcm_delay(subs, runtime->rate); /* update delay with exact number of samples played */ if (processed > subs->last_delay) @@ -1212,6 +1218,15 @@ static void retire_playback_urb(struct snd_usb_substream *subs, snd_printk(KERN_DEBUG "delay: estimated %d, actual %d\n", est_delay, subs->last_delay); + if (!subs->running) { + /* update last_frame_number for delay counting here since + * prepare_playback_urb won't be called during pause + */ + subs->last_frame_number = + usb_get_current_frame_number(subs->dev) & 0xff; + } + + out: spin_unlock_irqrestore(&subs->lock, flags); } @@ -1253,7 +1268,8 @@ static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substrea return 0; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: subs->data_endpoint->prepare_data_urb = NULL; - subs->data_endpoint->retire_data_urb = NULL; + /* keep retire_data_urb for delay calculation */ + subs->data_endpoint->retire_data_urb = retire_playback_urb; subs->running = 0; return 0; } |
