[linux-uvc-devel] 04f2:b2db is supported, with non-functional second video device

[Kevin L. <ke...@ke...>]

Hi all,

The ThinkPad T430 includes a "Chicony Electronics Co., Ltd." "Integrated
Camera" (04f2:b2db).  The camera works well with uvcvideo, but does not
currently appear on the Supported Devices list.[1]  There are two,
possibly related, oddities worth mentioning:

First, there are a few warnings printed when uvcvideo is loaded:

uvcvideo: Found UVC 1.00 device Integrated Camera (04f2:b2db)
uvcvideo 3-1.6:1.0: Entity type for entity Extension 4 was not initialized!
uvcvideo 3-1.6:1.0: Entity type for entity Extension 3 was not initialized!
uvcvideo 3-1.6:1.0: Entity type for entity Processing 2 was not initialized!
uvcvideo 3-1.6:1.0: Entity type for entity Camera 1 was not initialized!

Second, uvcvideo creates two video devices (video0 and video1):

$ readlink /sys/class/video4linux/video*
../../devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.6/3-1.6:1.0/video4linux/video0
../../devices/pci0000:00/0000:00:1a.0/usb3/3-1/3-1.6/3-1.6:1.0/video4linux/video1

`mpv /dev/video0` works well.  `mpv /dev/video1` fails with:

[ffmpeg/demuxer] video4linux2,v4l2: ioctl(VIDIOC_G_INPUT): Inappropriate ioctl for device

`v4l-info /dev/video1` shows:

### v4l2 device info [/dev/video1] ###
general info
    VIDIOC_QUERYCAP
	driver                  : "uvcvideo"
	card                    : "Integrated Camera: Integrated C"
	bus_info                : "usb-0000:00:1a.0-1.6"
	version                 : 5.8.7
	capabilities            : 0x84a00001 [VIDEO_CAPTURE,?,?,STREAMING,(null)]

standards

inputs

video capture
VIDIOC_G_FMT(VIDEO_CAPTURE): Invalid argument

controls

I don't understand the purpose of the second device (if any).  With
tracing enabled, there are references to "entity 1" and "entity 2" in
the kernel log.  Perhaps this is expected behavior?  If not, I would be
happy to help debug further.

Thanks for all of your efforts maintaining uvcvideo!

Best,
Kevin

[1]: https://www.ideasonboard.org/uvc/