AMD Finally Rolls Out New Linux Patches For Adaptive-Sync / VRR (FreeSync)

[JordanL]

\o/

There are some monitors/TVs implementing VRR via HDMI (I think the current Xboxes are capable of that) and it's also included in HDMI 2.1. I think once the work is done for DP, it will be relatively easy to extend to HDMI.

The patches here don't directly support HDMI VRR, but AFAIK the interface should be the same, so this lays the interface groundwork for that support some time in the future.

[M@GOid]

Once this lands and is usable, I will pull the trigger on a 34" ultrawide LG monitor I have a eye on since forever.

[perpetually high]

Source

AMD says that "FreeSync through HDMI will be supported on all AMD APUs and GPUs that already support FreeSync via DisplayPort, and AMD is working with ecosystem partners including LG, Samsung and Acer to deliver FreeSync over HDMI-compatible displays." That means existing FreeSync monitors won't magically start supporting variable refresh over HDMI, so you'll have to wait a few months to get a new monitor if you're looking for FreeSync support over HDMI.

TIL.

Separately, does anyone (hey bridgman) know how AMD goes about distributing these userspace bits? For example, say these patches get into mainline kernel, will the userspace changes be included in the "amdgpu-core" package of the latest AMD drivers? Or will they be in their own packages similar to how we install Vulkan and OpenCL?

So you'd need:

-FreeSync compatible monitor/GPU
-Kernel with these patches included
-AMD userspace bits
-FreeSync setting flipped on (DISPLAY=:0 xrandr --output DisplayPort-1 --set "freesync" 1)
-Vsync turned on in OpenGL app

Are those all the preconditions?

[haagch]

I have this monitor which claims to support "Freesync" but does not have a Displayport connector at all, just HDMI. I'm using it with a Displayport to HDMI adapter though. https://www.amazon.com/Dell-SE2717HR...dp/B01LXTK4T6/
If Freesync is officially only through Displayport, how can monitors like these claiming to support Freesync be sold?

[AsuMagic]

Holy shit! I literally bought a freesync monitor today. By the time it ships updates will be surely ready \o/

[AsuMagic]

I have this monitor which claims to support "Freesync" but does not have a Displayport connector at all, just HDMI. I'm using it with a Displayport to HDMI adapter though. https://www.amazon.com/Dell-SE2717HR...dp/B01LXTK4T6/
If Freesync is officially only through Displayport, how can monitors like these claiming to support Freesync be sold?

AFAIK it's supported through HDMI on Windows, but not on Linux. I remember reading that somewhere... Probably from an AMD team guy directly, actually.

[agd5f]

I have this monitor which claims to support "Freesync" but does not have a Displayport connector at all, just HDMI. I'm using it with a Displayport to HDMI adapter though. https://www.amazon.com/Dell-SE2717HR...dp/B01LXTK4T6/
If Freesync is officially only through Displayport, how can monitors like these claiming to support Freesync be sold?

It's supported via HDMI as well:

https://www.amd.com/en/technologies/free-sync-faq

[agd5f]

Source

TIL.

Separately, does anyone (hey bridgman) know how AMD goes about distributing these userspace bits? For example, say these patches get into mainline kernel, will the userspace changes be included in the "amdgpu-core" package of the latest AMD drivers? Or will they be in their own packages similar to how we install Vulkan and OpenCL?

So you'd need:

-FreeSync compatible monitor/GPU
-Kernel with these patches included
-AMD userspace bits
-FreeSync setting flipped on (DISPLAY=:0 xrandr --output DisplayPort-1 --set "freesync" 1)
-Vsync turned on in OpenGL app

Are those all the preconditions?

Once the kernel side lands, the userspace side (ddx, mesa) will as well. The current AMD specific implementation is already included in our packaged drivers. The upstream version will replace the AMD specific version in the packaged drivers once it goes upstream.

[perpetually high]

Once the kernel side lands, the userspace side (ddx, mesa) will as well. The current AMD specific implementation is already included in our packaged drivers. The upstream version will replace the AMD specific version in the packaged drivers once it goes upstream.

Beautiful, thanks for clarifying!

[haagch]

It's supported via HDMI as well:
https://www.amd.com/en/technologies/free-sync-faq

Okay, so it will be supported on Linux too? Thanks.

I was just going by the quotes here which made it sound like HDMI VRR was not really included in the Freesync umbrella. Glad to know it is.