Arch Linux

rennradler

Member

Registered: 2017-07-09

Posts: 7

[SOLVED] KDE: Composting broken

A resent update has broken composting on my machines. KDE Desktop effects are no longer working on my desktop and my notebook. Both are running nvidia drivers but different branches (340.xx and 381.xx). A Shift-Alt-F12 results in an error message:

kwin_x11[2493]: kwin_core: Compositing is not possible

The kwin version is 5.10.3.1-1 and kernel  version is 4.11.9-1-ARCH. Since there were quite a few packages updated (kernel, qt, plasma) it is hard to say which package caused the problem.

I scanned through the logs but I found no indication of what goes wrong.

Any ideas?

Last edited by rennradler (2017-07-09 15:33:42)

Potomac

Member

Registered: 2011-12-25

Posts: 528

Re: [SOLVED] KDE: Composting broken

can you run a 3D game without problem ?

or the tool "glxgears" from the mesa-demos package,
you can also run glxinfo in order to see if "direct rendering" is set to "Yes"

the idea is to check if 3D acceleration ( the use of openGL in hardware mode ) works

Last edited by Potomac (2017-07-09 15:01:20)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,258

Re: [SOLVED] KDE: Composting broken

This might be a potential detection issue, look into this thread for potential clues.

rennradler

Member

Registered: 2017-07-09

Posts: 7

Re: [SOLVED] KDE: Composting broken

Thank you very much. The problem is solved.

It was caused by these lines in .config/kwinrc on both machines:

[Compositing]
OpenGLIsUnsafe=true

I set it to false and now everything works again.

I looked into my backups. It was indeed added yesterday when I did the update.

YourPsychiatrist

Member

Registered: 2021-07-23

Posts: 1

Re: [SOLVED] KDE: Composting broken

Thank you very much. The problem is solved.

It was caused by these lines in .config/kwinrc on both machines:

[Compositing]
OpenGLIsUnsafe=true

I set it to false and now everything works again.

I looked into my backups. It was indeed added yesterday when I did the update.

That also did the trick for me. Created an account to say thank you! My backups indeed had this set to `false` as well. Reverting the updated file and restarting the display manager had everything go back to normal.