https://bugzilla.kernel.org/show_bug.cgi?id=206393
Alexander Jones (acjones8@hawaii.edu) changed:
What |Removed |Added ---------------------------------------------------------------------------- CC| |acjones8@hawaii.edu
--- Comment #7 from Alexander Jones (acjones8@hawaii.edu) --- I can also confirm this bug, I'm suffering the exact same problem with my ThinkPad A275. My glitchy screen looks like this: https://imgur.com/tKAxlI7
I'm also not able to restart X or switch VT, but I can confirm that the user applications still run, as I've heard Kmail issue a notification while the screen was glitchy. Other functions of the laptop, like the fan speed and keyboard illumination, still work perfectly after waking up and function like normal (if I press the shortcut to light the keyboard up, it changes intensity properly). Switching back to an older version of the kernel, 5.4.10 in my case, fixes the problem as well.
Curiously enough, I checked my dmesg for the SAD message after suspending with the older kernel, and it now reads this:
[ 5.450379] [drm] SADs count is: -2, don't need to read it
So it seems to be related to reading whatever the SAD is.