I am experiencing what I think may be a similar issue. When my display sleeps,
it often does not wake up on keypress. I have to wait anywhere from a few
seconds to a few minutes and then have errors in my log like the following

[drm:amdgpu_atombios_dp_link_train [amdgpu]] *ERROR* clock recovery failed
[drm:amdgpu_atombios_dp_link_train [amdgpu]] *ERROR* clock recovery failed

I am running Antergos 64-bit with GNOME 3.22.2 on Wayland
Kernels 4.8.13 and 4.10.0-rc3-ga121103c9228
AMD FX-8370 
Sapphire Fury X