Created attachment 139145 [details]
Xorg.0.log after crash

I have exactly the same blocky screen after logoff in SDDM with kernel 4.16.4
and RX 460. Xorg.0.log.amdgpu_logoff_crash contains xorg logs after crash.
Distro is gentoo, I have 3 screens connected to RX 460 - all get blocky screen.