(In reply to Michel Dänzer from comment #28)
> (In reply to Bernd Steinhauser from comment #27)
> > 
> > Although I'm not sure if it works as expected, since the display does still
> > seem to disconnect when I turn the screen off.
> 
> AFAIK that's either a monitor or general DisplayPort issue. The drivers
> can't prevent it but have to cope with it.

Quite possible. I've seen such behaviour on Windows as well on some displays.
Don't really get it, it's very annoying if your windows are rearrange just
because you turned off a display to save some power.

Anyway back to topic:
[595475.710884] [drm:amdgpu_atombios_dp_link_train] *ERROR* displayport link
status failed
[595475.710902] [drm:amdgpu_atombios_dp_link_train] *ERROR* clock recovery
failed

I do still get those messages sometimes, but at least I didn't experience any
lockups or freezes.