this post was submitted on 13 Mar 2024
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In the coming months, an important protocol will be merged to Wayland and xorg, and the next Nvidia driver release will have support for that protocol. This will make the Nvidia Wayland experience 100x better
Care to elaborate? Sounds promising
I’m not a hardware dev, but I’ve been following this issue for several months. Nvidia on Wayland does not implement implicit GPU synchronization currently for Xwayland. Other vendors do.
This issue is related to how/when the framebuffer from the gpu is handed off to be displayed. Implicit sync isn’t a great solution, it’s just what’s been done for Linux in the past.
Here’s a bit more detail if you’re interested:
I believe this issue is more specific to Wayland because Wayland relies on the DRM, direct rendering manager, to facilitate communication between the graphics driver and Wayland clients (applications). Whereas Xorg kinda just covered everything along the pipeline.
Implicit sync sounds like a bit of hack, where software (I assume the client? Or maybe the drm driver?) implicitly checks for the frame to be finished, rather than being signaled when the frame is ready.
So instead, Nvidia has been arguing for, designing and developing an explicit sync Wayland Protocol (and one for Xorg), which will let the graphics driver explicitly signal when a frame is finished and ready to be displayed. This is how the graphics stack works on Windows.
Right now on Nvidia, Xwayland clients will show previous frames, incomplete/corrupted frames or will fail to update when a new frame is rendered. Here’s the XWayland Merge Request. The issue is much worse on drivers > 535.xx after some optimizations worsened the issue. For now, rolling back can help!
There will be benefits in general with explicit sync, but the major ones will be Xwayland functioning properly for Nvidia users, VRR and apps with inconsistent framerates.
And apparently the plan is to have explicit sync ready for the next major driver version (v555).
From the discussions on Github and Gitlab it seems the work for that to happen is done. The changes in the necessary packages (Xwayland, Mesa?) just need to be merged and the the Nvidia driver 555 needs to be released. It hasn't been that long since the previous release 550. So I guess it is going to take a bit of waiting still.
Yeah, still gonna be a couple of months, but that is the last signifficant issue for me, fingers crossed.
It's the explicit sync protocol.
The TL;DR is basically: everyone else has supported implicit sync for ages, but Nvidia doesn't. So now everyone is designing an explicit sync Wayland protocol to accommodate for this issue.
It's explicit sync, look at my other comment for links
I'd like to know what this is as well? I was hoping Plasma 6 was going to solve my Nvidia + Wayland issues for me, but it didn't seem to make any difference.
I just replied to Nilz over here with my understanding of it.
The protocol is to facilitate explicit gpu synchronization.
Currently xwayland apps show the most issues with this on Nvidia. Driver 535 and earlier help mitigate it, or using native Wayland apps, when possible.
Because it's Nvidia drivers causing it.
That has already been established, yes.
PLEASE stop spreading that lie!!!
Why do you think it's a lie?
Wayland could have been written to support NVidia, just as X11 does. They chose not to because they hate the driver being proprietary. Wayland had the option to be and do a lot of things that the devs refused.
False, xorg isn't written with support for Nvidia, when xwayland windows flickers on Nvidia it's an effect of xorg not working Nvidia.
The Nvidia driver is a closed source implementation of the xorg server written by Nvidia for Nvidia GPUs. Xorg was invented at a time when drivers were done like that.
Now xorg uses glamor (except on Nvidia) which is a driver that implements the server over opengl, so you don't need to implement the whole thing for every GPU. Except glamor doesn't work on Nvidia because Nvidia doesn't implement implicit sync, which is required by Linux, and that is what you see in xwayland (which uses glamor as well).
Wayland doesn't require writing a whole server, but it requires implementing GBM and implicit sync (as does everything on Linux, unless you are using Nvidia's proprietary corgi server). Nvidia refused GBM until a few years ago, and still refuses to implement implicit sync. Which is why explicit sync will solve most issues.
That was a choice made by wayland devs not too use what was available. Their fault.
What is available is a x11 server, not more not less, it cannot be used for anything other than x11. If they made X12, it would not work on Nvidia, unless they wrote a new server, which they wouldn't.
You need to understand that the xorg server everyone use literally does not work on Nvidia, because it uses implicit sync, which is required by the Linux infrastructure. The only thing that works on Nvidia it's specifically their own proprietary server.
Nvidia does a lot of impressive stuff, but they have neglected the Linux scene for a long time, because it wasn't convenient, and it shows.
Edit: ...what was available... because Nvidia is gradually implementing things the correct way, and Wayland is becoming more and more usable with every driver update. Because, surprise surprise, it does depend on the drivers. Also, both Intel and AMD work perfectly with Wayland.
Read these
https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/59
https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/967#note_2323666
https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/90
https://github.com/NVIDIA/egl-wayland/pull/104
Plus, look for a merge request for your compositor, they are listed in the third link
Yeah, also waiting for it. Until the protocol is implemented, I have to use driver 535 without HDR support. :(