I dug a little deeper and using journalctl --since yesterday
I could retrieve a proper log. There are a couple of red and yellow entries, some of the latest ones being:
Feb 16 12:31:28 radium (udev-worker)[471]: event10: Failed to call EVIOCSKEYCODE with scan code 0x7c, and key code 190: Invalid argument
[…]
Feb 16 12:31:28 radium kernel: nvidia: loading out-of-tree module taints kernel.
Feb 16 12:31:28 radium kernel: nvidia: module license 'NVIDIA' taints kernel.
Feb 16 12:31:28 radium kernel: Disabling lock debugging due to kernel taint
Feb 16 12:31:28 radium kernel: nvidia: module verification failed: signature and/or required key missing - tainting kernel
Feb 16 12:31:28 radium kernel: nvidia: module license taints kernel.
[…]
Feb 16 12:31:37 radium kernel: NVRM: API mismatch: the client has the version 550.144.03, but
NVRM: this kernel module has the version 565.77. Please
NVRM: make sure that this kernel module and all NVIDIA driver
NVRM: components have the same version.
Feb 16 12:31:38 radium sddm[1280]: Failed to read display number from pipe
Feb 16 12:31:38 radium sddm[1280]: Display server stopping...
Feb 16 12:31:38 radium sddm[1280]: Attempt 3 starting the Display server on vt 2 failed
Feb 16 12:31:38 radium sddm[1280]: Could not start Display server on vt 2
The NVIDIA API warning appears several times throughout the log actually, which also implies I was wrong about driver version 560 being installed.
UPDATE:
I was able to recover my system by re-installing the NVIDIA drivers through, in my case,
sudo apt install nvidia-driver-550
since the kernel log indicated a version mismatch, presumably due to the Discover updates. Something’s still janky with the drivers as I experience massive lag and a ghosting cursor, but I’ll figure that out.I’d really appreciate tips on how to prevent this in the future.