[alsa-devel] question about webcam audio capture

vichy vichy.kuo at gmail.com
Sun Sep 8 17:24:48 CEST 2013


2013/9/8 vichy <vichy.kuo at gmail.com>:
> hi all:
> I try to do webcam audio capture on my arm platform.
> when I execute audio capture I got below message
> "retire_capture_urb: 108 callbacks suppressed"
>
> my questions:
> 1. where I can get the message "retire_capture_urb: 108 callbacks
> suppressed" show in sound/usb driver?
>     I try to  grep -rwn '"retire_capture_urb.*' sound/usb/*, but get nothing.
>
> 2. from usb mon log, it seems HW keep Active status high even until
> ehci_io_watchdog happen, because the ep status is  -EXDEV.
> if my observation is correct, is it possible to modify usb sound
> driver to purposely send fix number urbs.
> Because from the usb mon log, the first 8 urb will get time out already.
BTW, forget to say my kernel version is 3.8.2

>thanks for your help in advance,


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