Created attachment 139195 [details]
some kind of modern art by amdgpu.dc=1 upon logging out back into lightdm

Tried again on the RX580 box with amdgpu.dc=1. Computer did NOT freeze but
display did turn into some modern art project. ssh in shows this in the xorg
log
[   748.979] (EE) modeset(0): failed to set mode: Invalid argument
[   749.548] (II) modeset(0): Disabling kernel dirty updates, not required.
and nothing in dmesg.

interestingly service lightdm restart did bring it back up normally. logging
out again after that produced another pretty artistic ant-hive picture.