[alsa-devel] Missing exactly 3 of 8 audio packets?

[Daniel Griscom]

At 6:21 PM +0100 11/27/12, Clemens Ladisch wrote:
>Daniel Griscom wrote:
>>>  [  432.591698] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>>>  [  432.591702] ALSA sound/usb/pcm.c:1163 packet 1 failed: -18
>>>  [  432.592684] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>>>  [  432.592702] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>>>  [  432.592706] ALSA sound/usb/pcm.c:1163 packet 1 failed: -18
>>>  [  432.593684] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>>>  [  432.593701] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>>>  [  432.593705] ALSA sound/usb/pcm.c:1163 packet 1 failed: -18
>>>  [  432.594680] ALSA sound/usb/pcm.c:1163 packet 0 failed: -18
>
>These packet numbers never get above 1.  Are you using two
>microframes per URB?

We are using a bInterval value of 1 (on a high-speed device). We've 
recently tried bumping this up to 2, and the problem was no longer 
evident, but given the difficulty in reproducing it I wasn't at all 
clear that we hadn't just moved it to a different set of reproduce 
conditions.

... is that what you meant?

>What is the ALSA buffer size?

We're handing a value of 3072 to snd_pcm_hw_params_set_buffer_size_near().

>Regards,
>Clemens

Thanks,
Dan

-- 
Daniel T. Griscom             griscom at suitable.com
Suitable Systems              http://www.suitable.com/
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Wakefield, MA  01880-2400