AMD Caps Off Linux 7.4 Graphics Driver Development With More HDMI 2.1 Fixes

AMD on Thursday sent out a final pull request of their feature work aiming to be submitted for the upcoming Linux 7.4 merge window. This round of "few last odds and ends" is mostly about landing some bug fixes but of which there are a few worth mentioning. Pull requests in the prior weeks of AMDGPU/AMDKFD changes sent to DRM-Next for Linux 7.4 are already quite exciting. Most notably, HDMI 2.1 will be enabled by default for AMDGPU in Linux 7.4 now that the VRR and ALLM features are also in tow. Beyond that flurry of HDMI 2.1 activity, there is also new AMD hardware support for Linux 7.4 Following the HDMI 2.1 enabled-by-default, there has been a stream of follow-on fixes to the HDMI 2.1 code. That was again the case this week with more HDMI fixes ready for AMDGPU DC. One fix worth pointing out is the driver now sends the HDMI VRR metadata in the VTEM information packet slot. This should address a brief blank on HDMI outputs each time Variable Refresh Rate functionality is engaged or disengaged. There is also another patch to update the link training timeout bit as otherwise the HDMI link training compliance testing fails. AMD has been working on ensuring their AMDGPU HDMI 2.1 implementation achieves proper HDMI 2.1 compliance. This latest feature pull also enables direct scan-out alpha for some DRM formats, user queue "UserQ" fixes, fixes for the yet-to-be-released GFX12.1 hardware, SR-IOV fixes, and also UALink fixes. The full list of these AMDGPU and AMDKFD changes capping off the material for the Linux 7.4 merge window can be found via this pull request.