Tearing in WQHD, but not in FHD

Submitted by Torsten Kessler

Assigned to Default DRI bug account

Link to original bug (#103317)

Description

Created attachment 134888
X server log

Hi all,

I'm using Arch Linux with kernel 4.13.5-1-ARCH, Xorg 1.19.5 and the amdgpu driver, version 1.4. My GPU is a R9 390. I attached the X server log.
My window manager is i3.

Entries in xorg.conf.d:

20-amdgpu.conf

Section "Device"
Identifier "AMD R9 390"
Driver "amdgpu"
Option "DRI" "3"
Option "TearFree" "true"
EndSection

With this setup I experience screen tearing and flickering on a WQHD monitor.
Enabling a compositor like compton makes these effects worse.
I can reproduce this issue on the same machine with KDE instead of i3.
To give you an idea of my problem, I captured a scene from the RTS 0ad:

https://youtu.be/ZhjPpB7djyk

The same kind of flickering and tearing also happens in desktop mode. It seems to appear randomly.
However, the problem disappears when I'm using the radeonsi driver or changing the resolution to FHD. In both cases everything is fine.

Attachment 134888, "X server log":
xorg.log