AMD Sends Out New Linux Patches Further Enhancing HDMI 2.1 Reliability

Linux 7.4 is going to be the big kernel release where the AMD graphics driver will finally expose HDMI 2.1 by default and comes with features including HDMI FreeSync, VRR, and ALLM. Ahead of that milestone there have been various other last minute tweaks and improvements to its HDMI 2.1 support. Sent out on Thursday was the latest round of AMDGPU DC patches that includes a few more patches for improving the HDMI 2.1 reliability. The AMDGPU Display Core patches sent out for the week include improving HDMI 2.1 reliability. First up is a fix to skip HDMI FRL status polling when the link is down such as around hot-plugging actions to avoid the possibility of the display failing to light up. There is also a fix for the HDMI 2.1 LT timeout to better align with the HDMI specification to deliver a more consistent experience. The driver is also now serializing HDMI FRL status polling against link detect. Pretty minor changes but nice to see them working on HDMI 2.1 reliability ahead of the big Linux 7.4 merge window in October. The DC patches this week also work on new DCN 4.2 and DCN 6.0 support with various adjustments being made there. Based on the patch timing and the like, it appears DCN 6 will be coming with next-gen RDNA5 GPUs. The full list of these latest AMDGPU DC patches can be found on the mailing list. Separately, on Thursday was also the newest AMDGPU and AMDKFD pull request to DRM-Next for Linux 7.4 material. There the pull was made up of mostly fixes with a lot of work going on around AMD GFX12.1 IP as well as the DCN 6 display block.