I am using an HDMI to USB capture device that linux sets up as /dev/video0. It works like a webcam, but captures from HDMI. It works perfect using the vmlinuz-5.0.0-32-generic kernel. After updating to the vmlinuz-5.0.0-47-generic kernel, v4l2 does not set up the /dev/video device. After rebooting to the vmlinuz-5.0.0-32-generic kernel, the device works perfectly again. Hardware info: The computer is an ASUS M4A88T-M motherboard with no other pci cards installed, running linux Mint 19.3, 64-bit.
With new kernel (vmlinuz-5.0.0-47-generic) v4l2-ctl --all shows...
Failed to open /dev/video0: No such file or directory
With the older kernel (vmlinuz-5.0.0-32-generic) v4l2-ctl --all shows...
Driver Info (not using libv4l2):
Driver name : uvcvideo
Card type : UVC Camera (534d:2109): USB Vid
Bus info : usb-0000:00:12.2-4
Driver version: 5.0.21
Capabilities : 0x84A00001
Video Capture
Metadata Capture
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x04200001
Video Capture
Streaming
Extended Pix Format
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
Width/Height : 1920/1080
Pixel Format : 'MJPG'
Field : None
Bytes per Line : 0
Size Image : 4147200
Colorspace : sRGB
Transfer Function : Default (maps to sRGB)
YCbCr/HSV Encoding: Default (maps to ITU-R 601)
Quantization : Default (maps to Full Range)
Flags :
Crop Capability Video Capture:
Bounds : Left 0, Top 0, Width 1920, Height 1080
Default : Left 0, Top 0, Width 1920, Height 1080
Pixel Aspect: 1/1
Selection: crop_default, Left 0, Top 0, Width 1920, Height 1080
Selection: crop_bounds, Left 0, Top 0, Width 1920, Height 1080
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 30.000 (30/1)
Read buffers : 0
brightness 0x00980900 (int) : min=-128 max=127 step=1 default=-11 value=-11
contrast 0x00980901 (int) : min=0 max=255 step=1 default=148 value=148
saturation 0x00980902 (int) : min=0 max=255 step=1 default=180 value=180
hue 0x00980903 (int) : min=-128 max=127 step=1 default=0 value=0
Is there some way to get it working (modprobe or something) in the new kernel?
As a workaround, I can set up my PC to boot the the older kernel, but is this a problem a developer would be interested in knowing so that it could be corrected?
