Re: USB UVC webcam cannot capture

[Jerry Quinn <quinnj@gmail.com>]

Fixed! Apparently the camera isn't getting enough power.  Plugging it
directly into the machine instead of a USB port on the monitor enabled
the video.
Thank you for the suggestion.  It didn't occur to me that lower power
might create a partially usable device vs completely dead one.

I'll update and close the bug as well.

Thanks
Jerry Quinn


On Fri, May 23, 2025 at 1:21 AM Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> Hi Jerry
>
> In your dmesg I am seeing some
> usb 3-11.3: USB disconnect, device number 17
>
> I am not sure if that is you removing the camera or the camera
> deciding to leave the party on its own.
> Have you tried connecting the camera to a different port? And using a
> powered usb hub?
>
> If that doesn't work:
>
> Could you try to increase the trace level to the max?:
> rmmod uvcvideo; modprobe uvcvideo trace=0xffffffff
>
> And enabling v4l2 debugging:
> echo 255 > /sys/class/video4linux/video0/dev_debug
>
> Then capture a frame with v4l2-ctl or cheese.
>
> and then share the dmesg output.
>
> Thanks!
>
>
> On Fri, 23 May 2025 at 01:57, Jerry Quinn <quinnj@gmail.com> wrote:
> >
> > Hi folks,
> > I have a USB Sonix Technology L01 HD webcam that fails to capture
> > video.  I get a protocol error when trying to capture frames with the
> > current mainline kernel.
> >
> > I'm running the following to try to debug it:
> >
> > jlquinn@cerberus:~$ v4l2-ctl --device /dev/video0 --stream-mmap
> > --stream-to=frame.raw --stream-count=1
> > VIDIOC_STREAMON returned -1 (Protocol error)
> >
> > I've created a bugzilla report for this issue:
> > https://bugzilla.kernel.org/show_bug.cgi?id=220148
> >
> > This is the kernel build I used:
> > https://kernel.ubuntu.com/mainline/v6.15-rc7/amd64/
> >
> > jlquinn@cerberus:~/sw/src/cod/mainline/v6.15-rc7$ cat /proc/version
> > Linux version 6.15.0-061500rc7-generic (kernel@balboa)
> > (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-23ubuntu1) 14.2.0, GNU ld (GNU
> > Binutils for Ubuntu) 2.44) #202505182143 SMP PREEMPT_DYNAMIC Sun May
> > 18 22:13:39 UTC 2025
> >
> > jlquinn@cerberus:~/sw/src/cod/mainline/v6.15-rc7$ hostnamectl | grep
> > "Operating System"
> > Operating System: Ubuntu 24.04.2 LTS
> >
> >
> > My device is:
> > [ 2047.142578] usb 3-11.3: New USB device found, idVendor=26e0,
> > idProduct=6230, bcdDevice= 1.00
> > [ 2047.142594] usb 3-11.3: New USB device strings: Mfr=2, Product=1,
> > SerialNumber=3
> > [ 2047.142600] usb 3-11.3: Product: L01 HD Webcam
> > [ 2047.142604] usb 3-11.3: Manufacturer: Sonix Technology Co., Ltd.
> > [ 2047.142608] usb 3-11.3: SerialNumber: SN0001
> > [ 2047.144927] usb 3-11.3: Found UVC 1.00 device L01 HD Webcam   (26e0:6230)
> >
> > dmesg, lsusb, and v4lc-compliance output and kernel config are
> > attached to the bug report.
> >
> > Please let me know if I can provide anything else to help with looking
> > at this issue.
> >
> > Thanks
> > Jerry Quinn
> >
>
>
> --
> Ricardo Ribalda