AMDGPU FreeSync / Adaptive-Sync Is Set To Land For Linux 4.21

[zanny]

Just because its supported in kernel + Mesa doesn't mean the window systems or desktop shells will. Everything in the stack under the variable framerate program needs to support this.

Same reason we still don't have working bit depths > 8 yet. Requires programs, compositors, window managers, and hardware bits to all support it.

[perpetually high]

So does this work if you have something thats not very Linux-y, like having 2 Monitors?

As someone with dual 144hz FreeSync monitors, I laughed and then I cried

From what I remember, it only works on a single monitor plus a bunch of other preconditions. Whenever I game, I mirror both screens (via Feral's gamemode, and executing a script in the config on start= and stop= [1]) so I've stopped caring about FreeSync unfortunately. It just doesn't make sense to have my other monitor do nothing while I game (and it doesn't affect the FPS mirroring to both).

I've been very happy with this setup and TearFree.

[1]
# mirror
$ xrandr --output DisplayPort-0 --mode 1920x1080 --rate 144.00 --output DisplayPort-1 --mode 1920x1080 --rate 144.00 --same-as DisplayPort-0

# join
$ xrandr --output DisplayPort-0 --mode 1920x1080 --rate 144.00 --pos 1920x0 --output DisplayPort-1 --mode 1920x1080 --rate 144.00 --pos 0x0

[agd5f]

\o/
Does anybody know if any Wayland compositor's devs have said/done something concerning adaptive sync?

Yes, some of them were involved in the patch review discussions.

[shmerl]

Yes, some of them were involved in the patch review discussions.

That's good, hopefully it won't take very long for major DEs to provide support for it.

[rabcor]

This is great, but I wish we had this sooner.
I really hope that Intel and Nvidia implements support for this too.

Well, there was a workaround on windows where you could hook your display to your AMD card/apu and get freesync through that, but use your nvidia GPU for processing graphics in games https://www.youtube.com/watch?v=qUYRZHFCkMw

(I mean sure, it only really works with games that let you select the GPU used for graphical processing; but I'd be disappointed in the linux community if no one finds a system-wide workaround for this on Linux.)

[L_A_G]

Which is why it would be so awesome if Nouveau successfully implemented it and showed the world that it's possible

I wouldn't be that optimistic about it considering the pretty chronic lack of resources the Noveau people have been suffering from for years.

[Brisse]

I wouldn't be that optimistic about it considering the pretty chronic lack of resources the Noveau people have been suffering from for years.

True, but who knows, maybe once it's in place for Intel and AMD it's easy to port to Nouveau?

[haagch]

So does this work if you have something thats not very Linux-y, like having 2 Monitors?

Yea sure, very traditional that *nix workstations only run with a single monitor.

I too am using two monitors, so I read the patch message and it doesn't look like it.

The patches have been tested as working on upstream userland with the GNOME desktop environment under a single monitor setup. They also work on KDE in a single monitor setup with the compositor disabled. The patches require that suitable applications flip via the Present extension to xf86-video-amdgpu for the entire Screen. Some compositors may interfere with this if they are unable to unredirect the window.

[JordanL]

It would be good to know if the same restrictions apply to this as apply to AMD's closed source FreeSync support.

It should be a little more polished than the existing pro driver implementation. There are still some deltas between Windows and Linux support for Freesync, but they're being looked at for upcoming improvements. Having the proper support in DRM is the first step that can be used as a building block for further improvements.

Michael, small clarification: DP is supported today, HDMI VRR support can be added in the future using the same infrastructure.

[scix]

Just because its supported in kernel + Mesa doesn't mean the window systems or desktop shells will. Everything in the stack under the variable framerate program needs to support this.

Beyond mesa and the kernel, you only need a patched amdgpu ddx ( https://gitlab.freedesktop.org/kazla...-video-amdgpu ) to have working freesync, today. Although one caveat is that it doesn't work with Vulkan yet.