AMDGPU Driver Lacks HDMI 2.1 While AMD-Xilinx Driver Has Some HDMI 2.1 Support

Those following Phoronix and the open-source AMD Linux kernel graphics driver know that the HDMI Forum has prevented AMD from implementing HDMI 2.1 support in their open-source "AMDGPU" driver as due the driver implementation would run afoul to the organization's licensing requirements. It's been pointed out online this week that the AMD-Xilinx DRM driver though does have some HDMI 2.1 support albeit different hardware...