I updated Tumbleweed yesterday and following the update I began to experience flickering graphical artifacts. I’m using AMDGPU with RX 480 card and KDE.
I tried to capture a screenshot without luck, but basically there’s a scrambled multi-colored flickering in certain areas such as when a notification pops up or when I open a dropdown in firefox. The entire affected content area is covered with this scrambled multi-colored bars rather than the actual content, until I cause the display to refresh somehow.
I turned the hardware acceleration off in Firefox which resolved the issue in Firefox specifically but not across KDE obviously.
Is there a way to turn hardware acceleration off across Xorg? Is this a known bug that just cropped up or do I have failing hardware or … ?
Yes, I get that too, but with the radeon stack when used with glamor. exa renders properly whatever it is that the Plasma/Qt window stuff is asking to be done. You don’t have that choice with the amdgpu xorg driver (its glamor or its shadowfb/cpu). glamor gets the rendering done by translating requests into openGL and having the 3D part do it. Not everything translates well and can be slow. In other cases, such as this, something buggy is happening in the chain.
If its bothering you a lot, set the AccelMethod in the Device snippet file (/etc/X11/xorg.conf.d) to none. See man amdgpu for details.
When TW finally gets updated to xorg server v1.19, there are a lot of changes that affect glamor, and hopefully this issue will be taken care of, so you might wish to comment out any AccelMethod option you introduce and re-visit your experience utilizing glamor … if not (i.e. future testing reveals the same rendering glitches while utilising glamor), then hopefully a Plasma side update resolves the issue.
Cool, I didn’t see the AccelMethod setting. I’ll give that a shot soon. I wonder why this just introduced itself after the last update, though? Maybe a new configuration change was applied during the update.
Well, I’m using a different AMD device and different driver stack (radeon). But the glitching only began when I switched (from using exa) to using glamor Accel. It was generally minor at first. However, likely the same time as you reported this last week, I had noticed an intensification in the glitching. That said, I’ve since pulled in v1.19 of the X server, and the glitching, while still present, is much reduced (as I had hoped and anticipated it would be, given the improvements to glamor).
I don’t recall if the Modesetting/glamor combo produces the same glitching for me on my hardware, though I don’t suspect it would be any different (I will test it out in the near future again).
I tried adding
Option "AccelMethod" "none"
to the device section, but it caused a segmentation fault during boot when Xorg was starting, and just ended up in a never ending loop of trying to start the X server.
Well, that’s unfortunate.
But you have probably also now pulled in v1.19 of X, so I’d be curious if you’re still expereincing these artifacts, and, if so, if there has been any noticeable change.
I think I have fixed this by removing the TearFree option from the device in the X11 conf files (I had previously added this manually to stop tearing). I don’t have tearing even with this option removed, and the flickering seems to have gone away.
I get plenty of the glitches when resizing windows of other apps (like dolphin, Libreoffice, audacity, … ) … the during the window resizing, you get a macroblocked image (either of the application window or the underlining desktop background, or an image that you viewed recently but was still held in vram).
I just happen to use FF more, and so notice all its glitching more then I do with the others.
Tearfree (enabled or disabled) has no affect upon this for me.
I’m not going to bother changing FF’s rendering and wil stick with the defaults. IIRC, FF51 is supposed to bring in another change to accelerated layers, so will see what that brings.