Display goes black with Skype and Zoom

Hi, I am asking whether anyone has seen the following, and if so, how I can at least investigate what’s going on.

After a short time (10-30 min) in a Skype call (and lately also at least once in Zoom), both my screens suddenly go black. Almost all else is working: I can hear the other party, they can see me, I can ssh to the machine, but of course not go to the monitor (Alt-Ctrl-F1) because I can’t see it. I believe the keyboard might be dead (no response from the NumLock light) but can’t tell whether the mouse is dead as well. An attempt to shut the machine down from an ssh-session will kill the ssh session and the sshd process, i.e. I can not get back in with ssh, but NOT cleanly shut down the machine.

Since one common factor between SKype and Zoom is the use of a camera, I tried two different cameras from different manufacturers; the bug appears with both.

The only way I found to recover is power-off, with all that implies!

Any ideas (a) what might be the underlying issue, (b) how I could diagnose it, and (c) how to shut the machine down cleanly in this situation?

Thanks in advance,

System (as per YaST):
# Dell OptiPlex 9010
8 x Intel Core i7-3770 CPU 3.40GHz (it’s only quad-core really)
Main Memory 8 GB
Video: ATI Turks PRO [Radeon HD 7570]
Dell 1907FP and Dell 1908FP monitors
Web Cam Model: Microdia USB Live camera

I think the first thing you should tell is what desktop environment you are using.

Also, where these apps come from (rpm, flatpak, etc)

Next time look into journal within the ssh session: sudo journalctl -b

If you need, upload the log with susepaste.org and post the link here.

As for recovery, one way is enabling SysRq keys and holding Alt+SysRq, then pressing the sequence R E I S U B, it will reboot the machine. Also to restart Xorg you can press Ctrl+Alt+Backspace+Backspace. From ssh you should be able to schedule a shutdown with sudo shutdown -r in one minute.

KDE, plasmashell 5.18.6

It’s skyoeforlinux-64.rpm, downloaded from Microsoft originally and since maintained from their repository.

I really am under the impression that the keyboard is dead as well - the NumLock light does not respond to pressing that key. So that rules out any of your suggested keyboard actions.

The system journal does show something: from the timings, it looks like while the screen is dead it repeatedly has these entries:

Sep 08 11:29:33 msohni-home kernel: radeon 0000:01:00.0: ring 0 stalled for more than 29528msec
Sep 08 11:29:33 msohni-home kernel: radeon 0000:01:00.0: GPU lockup (current fence id 0x000000000028e246 last fence id 0x000000000028e
253 on ring 0)