Re: [Linux-uvc-devel] 174f:1420 Syntek malfunctions

[Andres C. <aci...@gm...>]

Hi again

> It sounds plausibly. But in this case i would expect error -28 (no
> space), rather then -110 (time out).
> Any way, currently only you can test if it's true. If you use debian you
> can probably use precompiled ubuntu kernels:
> http://kernel.ubuntu.com/~kernel-ppa/mainline/

I tested the latest 3 stable kernels: 2.6.39.4, 3.0.13 and 3.1.5 with
no luck. I actually cannot use a kernel lower than 3.0.x (permanently)
because it has no support for my realtek wireless card.

> If still no results, then try other quirks:
> #define UVC_QUIRK_STATUS_INTERVAL       0x00000001
> #define UVC_QUIRK_PROBE_MINMAX          0x00000002
> #define UVC_QUIRK_PROBE_EXTRAFIELDS     0x00000004
> #define UVC_QUIRK_BUILTIN_ISIGHT        0x00000008
> #define UVC_QUIRK_STREAM_NO_FID         0x00000010
> #define UVC_QUIRK_IGNORE_SELECTOR_UNIT  0x00000020
> #define UVC_QUIRK_FIX_BANDWIDTH         0x00000080
> #define UVC_QUIRK_PROBE_DEF             0x00000100
> #define UVC_QUIRK_RESTRICT_FRAME_RATE   0x00000200

Tried all the quirks one by one and nothing. The PROBE_DEF 0x100 quirk
is the only one that doesn't complain in dmesg. The others always
showed this:

[ 5626.340681] uvcvideo: UVC non compliance - GET_DEF(PROBE) not
supported. Enabling workaround.

> then if no results, test if device works at all with some alternate OS :)

Well, unfortunately this isn't an option for me. I could try, but I'm
not sure what that would accomplish, except getting the thing to work
properly. If this would help in bringing support for the linux kernel
then I would consider it.

Lastly I just want to share a few more of diagnostics I've tried:

1. Attached is the output from the CLI utility 'v4l2-compliance
--device=/dev/video0'. It shows a failure in one of the tests: test
VIDIOC_S_PRIORITY: FAIL (-1)

2. Also attached is the log of the utility guvcview when I try to use
with the webcam. It almost always fails...however it worked once
without a problem... how does this make any sense? how is it possible
that it works sporadically? Jitsi, ekiga and linphone fail right away,
but cheese and luvcview also works sporadically...

3. The webcam works flawlessly with the google talk plugin in
conjunction with Firefox 8.0. I know that this plugin uses the 32-bit
version of libv4l. While the other applications I've been trying are
native 64-bit. Thoughts? comments?

Thanks for your help, hopefully this new information will be helpful.
I didn't attach the kernel logs, because they are pretty much
identical.

Regards,

Andres