Hi Carmelo,
On Friday 01 August 2008, Carmelo Iannello wrote:
> Hi all,
>
> I recently bought a "Hercules Dualpix Chat and Show" webcam, after
> seeing it in the HCL of uvcvideo module.
> I hoped for it to work without any tweaking, but no luck.
> So I tried googling and trying to apply the suggested fixes but
> it didn't help.
> On Debian I installed the module with: module-assistant a-i linux-uvc
> revision 238, but I also tried with rv 239 from svn.
>
> At first, it complained giving this output in dmesg:
>
> Linux video capture interface: v2.00
> usbcore: registered new interface driver uvcvideo
> USB Video Class driver (v0.1.0)
> usb 4-5: new high speed USB device using ehci_hcd and address 5
> usb 4-5: configuration #1 chosen from 1 choice
> uvcvideo: Found UVC 1.00 device Hercules Dualpix Chat and Show Webcam
> (06f8:3007)
> uvcvideo: Failed to query (135) UVC control 1 (unit 0) : -32 (exp. 26).
> uvcvideo: Failed to query (129) UVC control 1 (unit 0) : -32 (exp. 26).
> uvcvideo: Failed to initialize the device (-5).
> 5:3:1: cannot get freq at ep 0x84
> usb 4-5: New USB device found, idVendor=06f8, idProduct=3007
> usb 4-5: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> usb 4-5: Product: Hercules Dualpix Chat and Show Webcam
> usb 4-5: Manufacturer: Guillemot Corporation
>
> Then I put in /etc/modprobe.d/uvcvideo:
> install uvcvideo /sbin/modprobe snd_usb_audio; /sbin/modprobe
> --ignore-install uvcvideo
>
> to postpone uvcvideo's loading to the usb audio's one,
> and also tried do to the same thing by hand, using insmod.
>
> The result is that the error msg about query 129 disappeared,
> the one about query 135 is still there, the module creates the
> /dev/video0 device, but the webcam doesn't work.
> Strangely, the webcam is not listed in lsusb's output.
>
> Any suggestion?
>
> Thanks,
> Carmelo
>
> PS
> Current dmesg output when I unplug and plug the camera:
>
> usb 4-5: USB disconnect, address 6
> usb 4-5: new high speed USB device using ehci_hcd and address 8
> usb 4-5: configuration #1 chosen from 1 choice
> uvcvideo: Found UVC 1.00 device Hercules Dualpix Chat and Show Webcam
> (06f8:3007)
> uvcvideo: Failed to query (135) UVC control 1 (unit 0) : -32 (exp. 26).
> input: Hercules Dualpix Chat and Show W as /class/input/input12
> 8:3:1: cannot get freq at ep 0x84
> usb 4-5: New USB device found, idVendor=06f8, idProduct=3007
> usb 4-5: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> usb 4-5: Product: Hercules Dualpix Chat and Show Webcam
> usb 4-5: Manufacturer: Guillemot Corporation
I'm not sure what goes wrong. Like many webcams, the Hercules Dualpix doesn't
implement the mandatory GET_DEF request on the video probe control, which
results in the 'Failed to query' error message. This should not be fatal as
the driver works around it, but it might confuse the webcam. Edit uvc_video.c
and replace the following code
if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 &&
(ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
return ret;
by
if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR) < 0)
return ret;
If this doesn't help, I'm not sure what else I can do. The 'cannot get freq'
message is printed by the usbaudio driver, so the problem seems to come from
the webcam. lsusb failing to list the camera is another hint that something
goes wrong at a low level. It could be a timing issue caused by subtle USB
timing differences between the platform the product is tested with (Windows)
and the platform you it them with. Nasty timing related bugs can surface when
the webcam is plugged into a Linux box even if it runs flawlessly under
Windows. Worse, your camera could work perfectly well on another Linux
computer. Those kind of issues tend to come quite often with UVC webcams.
Maybe the Hercules Dualpix uses a faulty USB chip (I would be interested in
knowing the chip brand and model if you can manage to open the case without
breaking anything).
You could also try not to load the usbaudio driver at all. Timing-related
issues that lead to a camera crash can be caused by many things, and
audio-related requests could crash a perfectly working video device.
Best regards,
Laurent Pinchart
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