Hi Guennadi,
On 11/04/18 10:56, Guennadi Liakhovetski wrote:
> Hi Laurent,
>
> Not sure whether that's a kernel or a user-space problem, but UVC related
> anyway. I've got a UVC 1.5 (!) Logitech camera, that used to work fine
> with earlier kernels. I now installed "media 4.16" and saw, that the
> kernel log was filling with messages like
>
> uvcvideo: Failed to query (GET_MIN) UVC control 2 on unit 1: -32 (exp. 1).
>
> The expected /dev/video[01] nodes were not created correctly, and the
> hard-drive was getting full very quickly. The latter was happening because
> the the /var/log/uvcdynctrl-udev.log file was growing. A truncated sample
> is attached. At its bottom you see messages
>
> [libwebcam] Warning: The driver behind device video0 has a slightly buggy
> implementation
> of the V4L2_CTRL_FLAG_NEXT_CTRL flag. It does not return the next higher
> control ID if a control query fails. A workaround has been enabled.
>
> repeating, which continues even if the camera is unplugged. The kernel is
> the head of the master branch of git://linuxtv.org/media_tree.git
>
> Just figured out this commit
>
> From: Edgar Thier <[email protected]>
> Date: Thu, 12 Oct 2017 03:54:17 -0400
> Subject: [PATCH] media: uvcvideo: Apply flags from device to actual properties
>
> as the culprit. Without it everything is back to normal.
I've already investigated and fixed this:
Please apply:
https://patchwork.kernel.org/patch/10299735/
You stated that this is showing up on a v4.16 kernel ... but as far as I'm aware
- this feature shouldn't make it in until v4.17. Are you using linux-next or a
media/master or such ?
Regards
Kieran
> Thanks
> Guennadi
>
