The integrated webcam has stopped working on Ubuntu 19.10 running on my XPS 13. Not sure if this was a breaking change in 18 or 19, but it definitely worked previously. Opening Cheese I just get 'No device found'.
The camera is definitely being detected by the system at least. Here's the output of dmesg:
$ dmesg | grep -i Camera
usb 2-5: Product: USB 2.0 Camera
uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6362
And these are the uvcvideo errors I get on startup:
.. kernel: [ 1046.126651] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:6362)
.. kernel: [ 1046.127803] uvcvideo: UVC non compliance - GET_DEF(PROBE) not supported. Enabling workaround.
.. kernel: [ 1046.128289] uvcvideo: Failed to query (129) UVC probe control : -32 (exp. 26).
.. kernel: [ 1046.128293] uvcvideo: Failed to initialize the device (-5).
This Dell forum thread suggests a fix for 9370 users has been incorporated in to the kernel, but this doesn't seem to be the case for me on 9343.