Comment 16 for bug 1969422

I came here from 1969351. On a rig with two identical AMD GPUs (First driving one monitor, second driving three), I'll sometimes have the one monitor disconnect, but it won't detect the failure or cause the other three screens to rearrange until I try to apply a change in Display Settings, after which it will show the one monitor as missing. The system will continue operating normally for a minute or two, before crashing back to the login screen

Dmesg shows these entries:
[127759.552431] gnome-shell[4403]: segfault at 558324328300 ip 0000558324328300 sp 00007ffd66257c98 error 15
[127780.586613] apport-gtk[272085]: segfault at 18 ip 00007fa1e6314cf4 sp 00007fff77ca9820 error 4 in libgtk-3.so.0.2404.29[7fa1e620c000+383000]
[130882.632498] traps: gnome-shell[272824] general protection fault ip:7f3228a412e7 sp:7ffe4c6be868 error:0 in libgbm.so.1.0.0[7f3228a40000+8000]
[176834.926719] gnome-shell[285277]: segfault at 501000000af ip 00007f250fbc92e7 sp 00007fff283ee988 error 4 in libgbm.so.1.0.0[7f250fbc8000+8000]

- Sometimes the system crashes to the login screen during a screen lock without any interaction
- Sometimes the system crashes to the login screen when attempting to unlock a locked session
- Sometimes after unlock a session shows all the windows rearranged or consolidated into a single workspace as though a monitor was briefly disconnected. Often windows are 'maximized' with a strange offset from a monitor's edge, which is fixed by re-maximizing the window.
- Sometimes after unlock everything is fine.

I have crash reports for the most recent failure in /var/crash, though I'm not sure how to provide them. _usr_bin_gnome-shell.1000.crash is nearly 70MiB