I have a iiyama gmaster monitor connected to an AMD TAHITI XT board using DP.
When the xserver switches it to dpms off, it has an hard time to get out of
this state: most of the time, the monitor is switched on but I get a "no
signal" error displayed by the monitor, and the graphic stack is trying to
restore the signal in a loop, unsuccessfully. That, whatever the refresh
rate:60Hz/120Hz/144Hz (1920x1080).
I provide the xserver log and the kernel.log while the components try to
restore the video signal.
linux amd-staging-next, drm git, llvm git, mesa git, xserver git,
xf86-video-amdgpu git, from this 20th of may.