Created attachment 139031 [details]
LightDM ant soccer

Starting with Linux 4.16.2, when I logoff from KDE Plasma, I don’t get back
into SDDM (just a black screen) or back into LightDM (wild random blocky
screen, see attachment).
I have a RX 580, DC is on. Same result on Linux 4.17rc2. Distro is
Antergos/Arch. Monitor is connected via DP.
Using SDDM, I can press ctrl + alt + F1 etc. to theoretically get to a tty
prompt but the screen does stay black. But then, after pressing ctrl + alt +
del numerous times, at least my system does a proper reboot. In LightDM, this
does not work and I have to use the reset button. Worked with Linux 4.16.1
before.