Since nvidia drivers do not properly implement implicit sync, this protocol not existing is the root cause of flickering with nvidia graphics on Wayland. This MR being merged means that Wayland might finally be usable with nvidia graphics with the next driver release.
EDIT: Nvidia dev posted that support is planned in the 555 driver, with beta release planned for May 15: https://github.com/NVIDIA/egl-wayland/pull/104#issuecomment-2010292221
Questions from someone still on xmonad/x11, with 3 computers that have nvidia cards:
Do all nvidia cards have trouble in wayland currently, or is it just some subset?
Is it really unususable, or just really annoyingly flickery?
Would my card be usable now (without this merge) if I was using the nouveau driver?
Once this is merged, will all nvidia cards work in wayland? Or do we not really know yet.
Nouveau should have already been fine, this should fix the proprietary driver's issues. AFAIK this is a core issue of the proprietary driver, so should affect all cards.
I tried Wayland on my 16xx series GPU, Electron apps were only annoying, but games were unplayable. The desktop itself and Wayland native apps worked fine, though.
I only have experience with my current GPU (3070 ti) and only in Hyprland, but the only flickering I have is in steam windows, everything else works flawlessly on 535 driver. Still excited that it may be fixed soon!
On 3060 mobile, there is flickering in steam and chrome, but it's usable. In chrome I believe it can be fixed by disabling hardware acceleration.
For what it's worth, I have only minor issues on wayland with nvidia, and all were fixable by changing some configuration option or something.
Maybe my demands aren't too heavy, but I do play games. I also use gentoo which makes fixing things easier.
Maybe if your games are Wayland native or you're still running the 535 driver? I saw fbdev=1 as a workaround, but that made things very jello-y.