Adaptive Sync enabling in Xorg Modesetting driver

Michel Dänzer michel at
Mon May 25 13:56:48 UTC 2020

On 2020-05-25 3:31 p.m., uday kiran pichika wrote:
> Hello,
> Am working on enabling the Adaptive sync feature as part of the
> Xorg/Modesetting DDX driver by taking the reference of AMD DDX Driver
> (xf86-video-amdgpu). Below is the commit which i submitted.
> I have made the below changes to enable this feature
> 1. Enable Adaptive sync in Graphics Driver
> 2. Added Xorg.conf file with VariableRefresh property which is read in the
> Modesetting driver --> This is working fine.
> After taking the above changes, am observing that Adaptive sync is not
> working.
> Below are my observations.
> 1. loader_dri3_helper.c  --> Adaptive sync property is being set once the
> system is booted successfully on one Window. Once
> set_adaptive_sync_property() method gets called, adaptive_sync_active flag
> is setting to true. From the next time, when fullscreen applications are
> loaded, this property never gets set on any window.
> 2. Once this property is being set, received a notification in modesetting
> ddx driver and read the property from the Stuff->window.
> 3. But when the fullscreen application(Either DOTA or Xonotic), not
> observing that this propety is not being set on any app window.
> Can any one please help me why this property is not being set in the
> application windows ?

>From your description, it does get set for some windows. Just apparently
not for the window which is fullscreen and using page flipping (your
description is a bit vague to be sure though).

Have you tried with a simpler test app, e.g.

 glxgears -fullscreen


Earthling Michel Dänzer               |     
Libre software enthusiast             |             Mesa and X developer

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