aboutsummaryrefslogtreecommitdiffstats
path: root/sound/usb
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2008-10-12 21:08:53 -0400
committerTakashi Iwai <tiwai@suse.de>2009-05-05 08:47:21 -0400
commitae1ec5e1e97f67d41e641a73380129e5905e41cc (patch)
treed6366e64044c20570724decdf2d6d10f1e476c97 /sound/usb
parent4bbe1ddf89a5ba3ec30fe5980912d8bda3a3cbb2 (diff)
ALSA: usbaudio - Add delay account
Manage the PCM delay account based on the queued URBs. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
-rw-r--r--sound/usb/usbaudio.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 823296d7d578..6c25fa23f702 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -627,6 +627,7 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
627 subs->hwptr_done += offs; 627 subs->hwptr_done += offs;
628 if (subs->hwptr_done >= runtime->buffer_size) 628 if (subs->hwptr_done >= runtime->buffer_size)
629 subs->hwptr_done -= runtime->buffer_size; 629 subs->hwptr_done -= runtime->buffer_size;
630 runtime->delay += offs;
630 spin_unlock_irqrestore(&subs->lock, flags); 631 spin_unlock_irqrestore(&subs->lock, flags);
631 urb->transfer_buffer_length = offs * stride; 632 urb->transfer_buffer_length = offs * stride;
632 if (period_elapsed) 633 if (period_elapsed)
@@ -636,12 +637,22 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
636 637
637/* 638/*
638 * process after playback data complete 639 * process after playback data complete
639 * - nothing to do 640 * - decrease the delay count again
640 */ 641 */
641static int retire_playback_urb(struct snd_usb_substream *subs, 642static int retire_playback_urb(struct snd_usb_substream *subs,
642 struct snd_pcm_runtime *runtime, 643 struct snd_pcm_runtime *runtime,
643 struct urb *urb) 644 struct urb *urb)
644{ 645{
646 unsigned long flags;
647 int stride = runtime->frame_bits >> 3;
648 int processed = urb->transfer_buffer_length / stride;
649
650 spin_lock_irqsave(&subs->lock, flags);
651 if (processed > runtime->delay)
652 runtime->delay = 0;
653 else
654 runtime->delay -= processed;
655 spin_unlock_irqrestore(&subs->lock, flags);
645 return 0; 656 return 0;
646} 657}
647 658
@@ -1520,6 +1531,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
1520 subs->hwptr_done = 0; 1531 subs->hwptr_done = 0;
1521 subs->transfer_done = 0; 1532 subs->transfer_done = 0;
1522 subs->phase = 0; 1533 subs->phase = 0;
1534 runtime->delay = 0;
1523 1535
1524 /* clear urbs (to be sure) */ 1536 /* clear urbs (to be sure) */
1525 deactivate_urbs(subs, 0, 1); 1537 deactivate_urbs(subs, 0, 1);