Specifically the "Display Controller (VOP)" ("VOP" = Video Out Processor). The HDMI PHY and bridge are slated for kernel 6.13-rc1. Without those, the HMDI controller can't send a picture. There are more portions too for 4K / 8K support, audio support, etc. But at the very least with the PHY and bridge working, I think that enables native kernel + Mesa support to get a picture and use Vulkan.
Kernel 6.12 was released today. The 6.13 development cycle should begin soon, although there's often a break over Christmas and New Year, so I'm expecting something early 2025 for a full working solution.
