Bug#723799: It doesn't just turn off monitors...

[Ralf-Peter Rohbeck <rrohbeck@gmail.com>]

Both monitors on the Displayports had switched off. I just left them off 
because I used only the other monitors at the time. After some time, one 
of the monitors turned back on. I wan't running with drm.debug so this 
is all I have:
Sep 19 16:34:12 ws kernel: [13419.456582] [drm:radeon_dp_link_train_ce] 
*ERROR* displayport link status failed
Sep 19 16:34:12 ws kernel: [13419.456585] [drm:radeon_dp_link_train_ce] 
*ERROR* channel eq failed
Seems like the displayport link is retried or something is flapping in 
the wind.