Firefox with WebRender and Xorg's TearFree option stops rendering when Xfce's compositor is on
It would seem that Xfce's compositor, when used with Xorg TearFree, makes Firefox's UI stop rendering.
Steps to reproduce:
- Enable xfwm compositor.
- Enable option Intel TearFree inside Xorg.conf as described here: https://wiki.archlinux.org/index.php/intel_graphics#Tearing
- set gfx.webrender.all to true in about:config inside Firefox
- reboot for changes to take effect
- open Firefox
Actual results:
Firefox ui draws only first frame and then completely freezes. Clicking buttons or switching tabs still seems to do things but without redrawing the ui. Only if you minimize and restore the firefox window will it redraw the ui. The cursor only changes if you place it on input fields.
Expected results:
Firefox draws the ui and works as usual.
The issue is not present if Xfce's compositor is disabled. Toggling between compositor on and off while Firefox is running makes the ui freeze as well. Reason why TearFree is useful for me: without it, i get screen tearing, even with Xfce's compositor on.
Original bug report on Mozilla's bugzilla
System info from about:support OS: Xubuntu 20.10
Please tell me if i can provide any other info, thanks.