https://bugs.freedesktop.org/show_bug.cgi?id=97025
--- Comment #28 from Michel Dänzer michel@daenzer.net --- (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.