[alsa-devel] [PATCH 1/5] ALSA: snd-usb: implement new endpoint streaming model

Daniel Mack zonque at gmail.com
Thu Nov 3 16:21:42 CET 2011

On 11/02/2011 04:49 PM, Clemens Ladisch wrote:
> Example with queue length = 2:
> 1) startup:
>     driver queues both capture URBs
> 2) 1st capture URB completes:
>     driver queues 1st playback URB and requeues 1st capture URB
> 3) 2nd capture URB completes:
>     driver queues 2nd playback URB and requeues 2nd capture URB
>     (all URBs are now queued)
> 4) 1st capture URB completes:
>     1st playback URB is still busy
>     (The playback URB might have been scheduled for a later frame, and
>     even for the same frame, there is no guarantee that the completions
>     for different endpoints happen in the same order as the queueing.)

I see. However, this really never happened in my tests so far. What 
would be a way to fix this? Queue less capture urbs than available slots 
for playback urbs?


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