AMDGPU HDMI 2.1 FRL To Be Initially Disabled-By-Default

One of the most exciting developments in recent times for the open-source AMDGPU kernel graphics driver is HDMI 2.1 FRL support for the AMDGPU driver along with Display Stream Compression support as they work toward providing full HDMI 2.1 support for this open-source AMD Radeon driver. The details how AMD managed to pull this feat off given prior resistance from the HDMI Forum remains to be confirmed, but it's moving ahead and out today is the latest iteration of the HDMI 2.1 FRL+DSC patches.

This sixth iteration of the HDMI FRL and FRL DSC patches was posted a few minutes ago to the mailing list. There are a few bug fixes but most notable is now making FRL disabled-by-default initially. Users wanting to enable HDMI 2.1 Fixed Rate Link support for higher refresh rates / resolutions will need to boot their Linux kernel with the amdgpu.dc_feature_mask=0x400 to enable the functionality.

FRL support is being disabled by default until the Variable Refresh Rate (VRR) functionality is in place. Without VRR support, it could be considered a regression for existing users with FRL-capable displays. Once the HDMI VRR support is ready, the plan is to have the support enabled by default. So the amdgpu.dc_feature_mask=0x400 necessity will hopefully be short-lived.

Those interested can check out the v6 patches on the mailing list. Here's to hoping it is submitted still in time for the upcoming Linux v7.2 cycle.