Created attachment 133913 [details]
dmesg

One or both monitors (ASUS much more often) continously blink once in 5-10
seconds. This happens only in linux and not in grub or windows. Second problem
is that monitor layout resets to mirrored from extended desktop when monitor
returns from powersaving to show lockscreen and I need to rerun xrandr. There
are some errors in dmesg, so it is attached. Log is from right after returning
from being AFK and giving lockscreen password. This bug is continuation to my
previous problem in Bug #102300.  

** System Info **

Ryzen 1700
ASUS Prime B350+
Radeon R9 285

Dell U2414H DVI-D-0 (HDMI -> DVI-D cable)
ASUS VE247  DVI-D-1 (DVI-I cable)

Graphics:  Card: Advanced Micro Devices [AMD/ATI] Tonga PRO [Radeon R9 285/380]
           Display Server: x11 (X.Org 1.19.3) driver: amdgpu
           Resolution: 1920x1080@60.00hz, 1920x1080@60.00hz
           OpenGL: renderer: Gallium 0.4 on AMD TONGA (DRM 3.19.0 /
4.12.0-1-amd-staging, LLVM 4.0.1)
           version: 4.5 Mesa 17.1.7

Linux zaplo-pc 4.12.0-1-amd-staging #1 SMP PREEMPT Sun Aug 27 18:23:36 UTC 2017
x86_64 GNU/Linux