Scratchy playback issue with USB CLASS2 audio device

[Hans Petter Selasky]

On 10/19/13 08:35, Hans Petter Selasky wrote:
> On 10/19/13 07:46, Taner wrote:
>> uaudio_chan_play_sync_callback: Value = 0x0005fff8
>> uaudio_chan_play_sync_callback: Comparing 47998 < 48000
>> uaudio_chan_play_sync_callback: Value = 0x0005fff6
>> uaudio_chan_play_sync_callback: Comparing 47998 < 48000
>
> Hi,
>
> The normal for adaptive rates is that this value should tilt just above
> or below the 48000 or whatever is there. Else something is wrong.
>
> Did you try to record while playing?
>
> Also, are you running -stable?
>
> Could also check the amount of samples sent by using
> "usbdump -i usbusX -f Y -s 65536 -vvv"
>
> --HPS

Hi,

Does this patch make any difference?

=== dev/sound/usb/uaudio.c
==================================================================
--- dev/sound/usb/uaudio.c	(revision 256754)
+++ dev/sound/usb/uaudio.c	(local)
@@ -2070,7 +2070,7 @@
  		chn_intr(ch->pcm_ch);

  		/* start SYNC transfer, if any */
-		if ((ch->last_sync_time++ & 7) == 0)
+		if ((ch->last_sync_time++ & 3) == 0)
  			usbd_transfer_start(ch->xfer[UAUDIO_NCHANBUFS]);

  	case USB_ST_SETUP:

--HPS