New MS2106 Easycap
There's a new Easycap variant using the Macro Silicon M2106 chip [] which is a USB video class device but as of kernel 5.1.0 it is not supported.
These can be identified by the USB ID 534d:0021.
The fix would probably involve adding a quirk to the kernel UVC driver, unfortunately I don't have the time to do that.
Kernel dmesg output
[47451.958468] usb 1-2.1.2: new high-speed USB device number 46 using xhci_hcd [47452.093453] usb 1-2.1.2: New USB device found, idVendor=534d, idProduct=0021, bcdDevice= 1.21 [47452.093455] usb 1-2.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [47452.093457] usb 1-2.1.2: Product: AV TO USB2.0 [47452.093458] usb 1-2.1.2: Manufacturer: MACROSILICON [47452.093459] usb 1-2.1.2: SerialNumber: 20150130 [47452.098283] uvcvideo: Found UVC 1.00 device AV TO USB2.0 (534d:0021) [47452.103222] uvcvideo: UVC non compliance - GET_DEF(PROBE) not supported. Enabling workaround. [47452.106292] uvcvideo 1-2.1.2:1.0: Entity type for entity Processing 2 was not initialized! [47452.106295] uvcvideo 1-2.1.2:1.0: Entity type for entity Camera 1 was not initialized! [47452.176245] usb 1-2.1.2: Warning! Unlikely big volume range (=8191), cval->res is probably wrong. [47452.176248] usb 1-2.1.2:  FU [Mic Capture Volume] ch = 1, val = 0/8191/1 [47457.255634] hid-generic 0003:534D:0021.0015: hiddev0,hidraw1: USB HID v1.10 Device [MACROSILICON AV TO USB2.0] on usb-0000:01:00.0-2.1.2/input4 [47457.277988] systemd-udevd: Process '/usr/sbin/alsactl -E HOME=/run/alsa restore 2' failed with exit code 99.
After trying to run mplayer we get:
[47463.359411] uvcvideo: Failed to set UVC probe control : -32 (exp. 26). [47464.897428] uvcvideo: Failed to set UVC probe control : -32 (exp. 26). [47470.833473] uvcvideo: Failed to set UVC probe control : -32 (exp. 26). [47478.621602] uvcvideo: Failed to set UVC probe control : -32 (exp. 26). [47480.121688] uvcvideo: Failed to set UVC probe control : -32 (exp. 26).