regression: broken vsync and VRR for fullscreen windows in XOrg session
OS: Arch Linux
issue is specific to XOrg
xorg-server 21.1.8 using modesetting ddx
GPU: AMD RX 6700XT on Mesa 23.0.3
Since gnome/mutter was updated to version 44.1 in Arch Linux, vsync and variable refresh rate is broken for unredirected fullscreen windows when using the XOrg session on a single monitor, which results in visible tearing. The issue was not present in version 43.5, which was shipped by Arch previously. Fullscreen window unredirection seems to still work properly though. E.g. when running
Meta.add_debug_paint_flag(Meta.DebugPaintFlag.OPAQUE_REGION) in looking glass, I can see the debug overlay going away when a window is fullscreened.
Steps to reproduce
- run gnome on xorg with only a single monitor enabled
- play a video using mpv or vlc and make it fullscreen
- observe the video tearing due to not working vsync
Mutter introduced tearing in fullscreen windows.
What did you expect to happen
No tearing in fullscreen windows, like it was with mutter 43.5 and earlier versions.
Relevant logs, screenshots, screencasts etc.
Not sure what would be relevant, I don't see anything interesting being logged. I tried to bisect this issue, but I'm currently having trouble with the gnome-shell <> mutter dependency and I'm experiencing crashes when I try to run my gnome-shell+mutter builds with
gnome-shell --replace, if there is a guide somewhere on how to bisect gnome-shell+mutter, please point me to that.