Linux 5.12 Bringing VRR / Adaptive-Sync For Intel TIger Lake / Xe Graphics
The VRR/Adaptive-Sync support for the latest-generation Intel graphics with Tiger Lake and the likes of the forthcoming Rocket Lake, Alder Lake, and discrete DG1 graphics is now in order for the mainline kernel. The VRR enabling for Tiger Lake and newer was sent in this morning to DRM-Next ahead of the Linux 5.12 kernel. This effort has been going on for many months while now has reached the stage that it's ready for merging.
This support is exposed only for DisplayPort / eDP connections. The lack of HDMI interface support appears to be due to the same reason AMD can only provide open-source VRR/Adaptive-Sync over DisplayPort and not HDMI: the HDMI Forum preventing so in closing up the public specification access and in turn preventing open-source GPU drivers from divulging any non-public portions of the spec.
So those with a VRR-capable DP/eDP display and using Tiger Lake graphics or newer will be able to enjoy the adaptive synchronization experience in trying to avoid tearing and stuttering. This VRR/Adaptive-Sync support will become all the more important when Intel introduces their higher performance / gaming graphics cards moving ahead.
The code was part of today's drm-intel-next pull along with enabling High Definition Content Protection (HDCP) versions 2.2 and 1.4 for Gen12/Xe DisplayPort Multi-Stream Transport (DP MST) interfaces, display code clean-ups and refactoring, workarounds for the DG1 discrete graphics card, and clear color support for Tiger Lake.
This is the last main feature pull request for the Intel graphics driver with the upcoming Linux 5.12 merge window next month given that the soft cutoff of new Direct Rendering Manager code is coming up with the Linux 5.11-rc6 due out this weekend.