Bugzilla – Bug 1120172
KDE Plasma screen tearing in X11 with Intel GPU
Last modified: 2019-01-25 08:28:29 UTC
The screen tearing happens after recent snapshot update 2018-12-19. This makes the system totally unusable. It only happens in KDE Plasma X11 session with Intel GPU. It doesn't happen in KDE Plasma Wayland session or with AMD GPU. My CPU is Intel Core i7-4710HQ. My GPU is Intel HD Graphics 4600.
Video record of screen tearing is here: https://www.reddit.com/r/kde/comments/a8239k/kde_x11_starts_to_flicker_today_but_wayland_works/
Did also see this problem (but only on second concurrent session), but a later upgrade fixed it.
Sorry, the reddit Video doesn't work for me? Could you attach it to this bugreport instead? Thanks!
Created attachment 793713 [details] Video camera recording
The uploaded attachment seems incomplete. I also tried to upload to YouTube https://youtu.be/2nOPeLQlRcg The only solution I found is to remove package xf86-video-intel.
(In reply to Yunhe Guo from comment #5) > The uploaded attachment seems incomplete. I also tried to upload to YouTube > https://youtu.be/2nOPeLQlRcg > > The only solution I found is to remove package xf86-video-intel. Well, we no longer install this package by default for Intel GPUs Gen >=4. You have Haswell, which is I believe Gen 8 or alike.
(In reply to Stefan Dirsch from comment #6) > Well, we no longer install this package by default for Intel GPUs Gen >=4. > You have Haswell, which is I believe Gen 8 or alike. I might install the package manually before. So it is still in my system.
(In reply to Yunhe Guo from comment #7) > (In reply to Stefan Dirsch from comment #6) > > Well, we no longer install this package by default for Intel GPUs Gen >=4. > > You have Haswell, which is I believe Gen 8 or alike. > > I might install the package manually before. So it is still in my system. I know. And thanks for the Youtube video!
My report #1122227 is probably a duplicate of this. (In reply to Stefan Dirsch from comment #6) > > The only solution I found is to remove package xf86-video-intel. > > Well, we no longer install this package by default for Intel GPUs Gen >=4. > You have Haswell, which is I believe Gen 8 or alike. Interesting, so openSUSE now defaults to X modesetting for Intel?
(In reply to S. B. from comment #9) > Interesting, so openSUSE now defaults to X modesetting for Intel? Fedora did it 2 years ago. Debian did it 30 months ago. I did it on all my openSUSEs 2 years ago, except for those too old for modesetting support.
xf86-video-intel works very well on my UHD 630. It seems to enable TearFree by default (which works great) allowing to not have to use a compositor in simple environments such as i3wm or just using a Window Manager.
(In reply to Michael Pujos from comment #11) > xf86-video-intel works very well on my UHD 630. > It seems to enable TearFree by default (which works great) allowing > to not have to use a compositor in simple environments such as i3wm or just > using a Window Manager. Yes, the serious bugs with xf86-video-intel seem to pop up mainly with Plasma's compositor. https://forum.kde.org/viewtopic.php?t=127575 Who knows who really is at fault, Plasma devs tend to blame xf86-video-intel for having subtle bugs that only the Plasma compositor manages to reveal.
(In reply to S. B. from comment #12) > Yes, the serious bugs with xf86-video-intel seem to pop up mainly with > Plasma's compositor. > https://forum.kde.org/viewtopic.php?t=127575 > Who knows who really is at fault, Plasma devs tend to blame xf86-video-intel > for having subtle bugs that only the Plasma compositor manages to reveal. Actually it can work perfectly without glitches in Plasma, but you have to set 'Tearing prevention ("vsync")' to 'Never' in Plasma Compositor settings. Basically you disable vsync in the compositor and let the Intel driver handle it. Otherwise they seem to fight each other resulting in a corrupted display.
(In reply to Michael Pujos from comment #13) > (In reply to S. B. from comment #12) > > xf86-video-intel > > Actually it can work perfectly without glitches in Plasma, but you have to > set 'Tearing prevention ("vsync")' to 'Never' in Plasma Compositor settings. > Basically you disable vsync in the compositor and let the Intel driver > handle it. Otherwise they seem to fight each other resulting in a corrupted > display. Interesting tip! Thanks, I'll have to try that.
This is probably related to bug#1120090.
(In reply to S. B. from comment #14) > (In reply to Michael Pujos from comment #13) > > (In reply to S. B. from comment #12) > > > xf86-video-intel > > > > Actually it can work perfectly without glitches in Plasma, but you have to > > set 'Tearing prevention ("vsync")' to 'Never' in Plasma Compositor settings. > > Basically you disable vsync in the compositor and let the Intel driver > > handle it. Otherwise they seem to fight each other resulting in a corrupted > > display. > > Interesting tip! Thanks, I'll have to try that. NEEDINFO
I can confirm this bug is fixed as of today by the latest TW snapshot with this: ==== kwin5 ==== Subpackages: kwin5-lang - Add patch to force initialization of OpenGL to fix flickering (boo#1120090, QTBUG-73122): * 0001-Fix-flickering-with-Qt-5.12.patch So I think you can close this bug as fixed.
(In reply to Stefan Dirsch from comment #16) > (In reply to S. B. from comment #14) > > (In reply to Michael Pujos from comment #13) > > > (In reply to S. B. from comment #12) > > > > xf86-video-intel > > > > > > Actually it can work perfectly without glitches in Plasma, but you have to > > > set 'Tearing prevention ("vsync")' to 'Never' in Plasma Compositor settings. > > > Basically you disable vsync in the compositor and let the Intel driver > > > handle it. Otherwise they seem to fight each other resulting in a corrupted > > > display. > > > > Interesting tip! Thanks, I'll have to try that. > > NEEDINFO Still on TW 20190115 this is what I found: - Xmodesetting + openGL 3.1 + tearing prevention (auto) = good - Xmodesetting + openGL 3.1 + tearing prevention (never) = large black glitches - Xmodesetting + openGL 2.0 + tearing prevention (never) = good - xf86-video-intel + openGL 2.0 or 3.1 + tearing prevention (never) = good
Interesting. How did you switch between OpenGL 2.0 and 3.1?
(In reply to S. B. from comment #18) > (In reply to Stefan Dirsch from comment #16) > > (In reply to S. B. from comment #14) > > > (In reply to Michael Pujos from comment #13) > > > > (In reply to S. B. from comment #12) > > > > > xf86-video-intel > > > > > > > > Actually it can work perfectly without glitches in Plasma, but you have to > > > > set 'Tearing prevention ("vsync")' to 'Never' in Plasma Compositor settings. > > > > Basically you disable vsync in the compositor and let the Intel driver > > > > handle it. Otherwise they seem to fight each other resulting in a corrupted > > > > display. > > > > > > Interesting tip! Thanks, I'll have to try that. > > > > NEEDINFO > > Still on TW 20190115 this is what I found: > > - Xmodesetting + openGL 3.1 + tearing prevention (auto) = good > - Xmodesetting + openGL 3.1 + tearing prevention (never) = large black > glitches > - Xmodesetting + openGL 2.0 + tearing prevention (never) = good > - xf86-video-intel + openGL 2.0 or 3.1 + tearing prevention (never) = good The fix I mentioned is in TW 20190121 released today so you may want to try it.
> The fix I mentioned is in TW 20190121 released today so you may want to try > it. Specifically for me: xf86-video-intel + openGL 2.0 + tearing prevention (auto) = good Previously it had large black glitches.
(In reply to Stefan Dirsch from comment #19) > Interesting. How did you switch between OpenGL 2.0 and 3.1? https://i.imgur.com/09Vjqfn.png
(In reply to Michael Pujos from comment #20) > > > > Still on TW 20190115 this is what I found: > > > > - Xmodesetting + openGL 3.1 + tearing prevention (auto) = good > > - Xmodesetting + openGL 3.1 + tearing prevention (never) = large black > > glitches > > - Xmodesetting + openGL 2.0 + tearing prevention (never) = good > > - xf86-video-intel + openGL 2.0 or 3.1 + tearing prevention (never) = good > > The fix I mentioned is in TW 20190121 released today so you may want to try > it. Thanks, the fix seems to work. Now I'm using xf86-video-intel + openGL 3.1 + tearing prevention (Automatic) and I haven't seen any glitches yet.
Thanks to everyone helping to fix this issue!
(In reply to Stefan Dirsch from comment #24) > Thanks to everyone helping to fix this issue! Yes, I neglected to say this, many thanks for the fix!
(In reply to Michael Pujos from comment #17) > I can confirm this bug is fixed as of today by the latest TW snapshot with > this: > > ==== kwin5 ==== > Subpackages: kwin5-lang > > - Add patch to force initialization of OpenGL to fix flickering > (boo#1120090, QTBUG-73122): > * 0001-Fix-flickering-with-Qt-5.12.patch > > > > So I think you can close this bug as fixed. Let's mark it as duplicate then... *** This bug has been marked as a duplicate of bug 1120090 ***