Hi,
Updating to mesa-git-20.3.0_devel.128278.20a4235c4c9-1 caused a kwin_x11 crash, preventing it to use OpenGL as the compositor engine which resulted in a sluggish device (even after rebooting it).
After rebooting, the crash didn’t happen again, but it appeared that I’d lost transparency (during animations like moving windows, using the drop-down terminal, moving the mouse cursor, even the shutdown menu background was completely black) and the system felt sluggish when it used to display transparency before the update (like it was dropping frames and it kinda felt like it was using the CPU instead of the GPU to render the desktop).
To fix this, downgrade mesa-git to the previous version (mesa-git-20.3.0_devel.127750.ac6b8e42ce2-1), then go to System Settings > Hardware > Display and Monitor > Compositor. There should be a message on top saying that OpenGL detection was turned off because it caused crashes in the past and asking to re-enable it. Re-enabling it and rebooting fixed the issue for me.
Updating to mesa-git-20.3.0_devel.128278.20a4235c4c9-1 caused a kwin_x11 crash, preventing it to use OpenGL as the compositor engine which resulted in a sluggish device (even after rebooting it).
After rebooting, the crash didn’t happen again, but it appeared that I’d lost transparency (during animations like moving windows, using the drop-down terminal, moving the mouse cursor, even the shutdown menu background was completely black) and the system felt sluggish when it used to display transparency before the update (like it was dropping frames and it kinda felt like it was using the CPU instead of the GPU to render the desktop).
To fix this, downgrade mesa-git to the previous version (mesa-git-20.3.0_devel.127750.ac6b8e42ce2-1), then go to System Settings > Hardware > Display and Monitor > Compositor. There should be a message on top saying that OpenGL detection was turned off because it caused crashes in the past and asking to re-enable it. Re-enabling it and rebooting fixed the issue for me.