Odd lower or upper screen tear with 6800xt amdgpu

Support KDE Plasma
1

I have this odd issue which MAY be a driver/mesa problem but I can’t quite understand it,.

The problem occurs normally after I leave the desktop idle for a while, or if the screen goes to lock-screen. I’ve since turned off energy saving on screen because when that triggers it also.

The way to resolve the bug is to set 30hz, then back to 60hz again. I have tearfree and variable refresh toggled on in the xorg conf.

Seems there is a driver or kwin bug happening. I am using kwin-lowlatency btw.

If anyone else gets this sort of issue with amdgpu please do tell. I may only affect NAVI2 cards, or perhaps it happens to navi1 also? I do not know.

2

possible.
You would have to check with and without to tell us if so.

3

It seems to happen when monitor goes into standby or if I turn off my monitor for long enough.

Never happened on my 1080TI when I had that installed.

I suspect the freesync option I’ve enabled so will be testing with that off first.

4

Can confirm this seems to be a freesync issue, I’ve see variations of this happening on my nvidia 1080ti but it was not consistent and didn’t happen too often.

It seems AMDGPU freesync however will cause this issue to happen all the time if you turn off the display for long enough and then re-enable it.

Could probably be fixed, but perhaps its unique to my particular display which is a QNIX 40" 4k@60hz curved display (no longer sold).

5

You can try throwing the ‘tearfree’ option into an xorg conf. couldnt hurt I guess. :

/etc/X11/xorg.conf.d/99-amdgpu.conf

Section "Device"
     Identifier "AMD"
     Driver "amdgpu"
     Option "TearFree" "True"
     Option "SWCursor" "True"
 EndSection

Thats mine … you can ignore the SWCursor … its for rendering the pointer using software.

EDIT. Doh. Of course … there is also an option which I dont need but is perfect for you:

Option "VariableRefresh" "true"

(PS to check your screen is variable refresh capable use xrandr --props to check for vrr_capable)

6

Yes I have those. And it seems after updating mesa and kernel to latest the problem MAY have gone away, for now…

7

Hey there, I have exactly the same issue with my new screen when FreeSync is turned on. I’m using an Asus VG249Q1R and a 5600XT on Kubuntu 20.04 so it does not seem to be screen or environment related, rather a driver/OS bug. I already activated VRR and Tearfree in the 10-amdgpu.conf.

To which mesa and kernel version did you update @theriddick?

8

This issue still happens if I turn off freesync in the xorg config (I have it mirrored to manjaro hw dir).

It seems to be happening at the bottom quarter of screen, and sometimes when first boot into Plasma, or when I go afk and the idle screen shots up.

I’ve tried all mesa and mesa-dev-git, kwin and kwin-lowlatency. I would say the kwin-lowlatency seems to trigger the issue more possibly…

I believe the issue goes away if you turn off freesync via the monitor.

Note: This issue does not occur under windows.