[alsa-devel] Regression in sound/usb/

[Daniel Mack]

On 05.07.2012 17:32, Philipp Dreimann wrote:
> On 5 July 2012 16:41, Takashi Iwai <tiwai at suse.de> wrote:
>>> Try the patch below.  If it still doesn't work, give the kernel
>>> message again and lsusb -v output, too.
>>
>> Did it make any difference?
> 
> No, it unfortunately did not.
> 
> lsusb is attached and the parts of the kernel log are in the mail:
> 
> [   41.243211] usb 2-1.2: new high-speed USB device number 3 using ehci_hcd
> [   41.605666] uvcvideo: Found UVC 1.00 device <unnamed> (046d:0821)
> [   42.002275] input: UVC Camera (046d:0821) as
> /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.2/input/input12
> [   42.085880] usbcore: registered new interface driver snd-usb-audio
> 
> [   52.790139] uvcvideo: Failed to query (GET_DEF) UVC control 2 on
> unit 2: -71 (exp. 2).
> [   52.794363] uvcvideo: Failed to query (GET_DEF) UVC control 2 on
> unit 2: -71 (exp. 2).
> [   52.798375] uvcvideo: Failed to query (GET_DEF) UVC control 3 on
> unit 2: -71 (exp. 2).
> [   52.802499] uvcvideo: Failed to query (GET_DEF) UVC control 7 on
> unit 2: -71 (exp. 2).
> [   52.806617] uvcvideo: Failed to query (GET_DEF) UVC control 11 on
> unit 2: -71 (exp. 1).
> [   52.810734] uvcvideo: Failed to query (GET_DEF) UVC control 4 on
> unit 2: -71 (exp. 2).
> [   52.814855] uvcvideo: Failed to query (GET_DEF) UVC control 5 on
> unit 2: -71 (exp. 1).
> [   52.818976] uvcvideo: Failed to query (GET_CUR) UVC control 11 on
> unit 2: -71 (exp. 1).
> [   52.823096] uvcvideo: Failed to query (GET_DEF) UVC control 8 on
> unit 2: -71 (exp. 2).
> [   52.827215] uvcvideo: Failed to query (GET_DEF) UVC control 1 on
> unit 2: -71 (exp. 2).
> [   52.831331] uvcvideo: Failed to set UVC probe control : -71 (exp. 26).
> [   52.835459] uvcvideo: Failed to set UVC probe control : -71 (exp. 26).
> The last line repeats a few times, then the Failed to query block
> repeats again, and so on. But only if I try to use the webcam.
> 
> [   82.363599] 3:1:3: cannot set freq 32000 to ep 0x86
> Is showing up without using the webcam.
> 

What really puzzles me is that the uvcvideo code fails as well, and even
before the sound driver bails out. If you wouldn't have bisected the
problem, I would clearly blame some other change for that.

It seems something confuses the device quite badly so requests to it
return -EPROTO. From a quick grep, this error can only be originated
from low-level EHCI functions.

I need to ponder on that a little ...


Daniel