Brief summary of the problem: I have a RX 6800 XT connected to a LG B9 TV via HDMI. As both...
Alex Deucher:
The HDMI Forum has rejected our proposal unfortunately. At this time an open source HDMI 2.1 implementation is not possible without running afoul of the HDMI Forum requirements.
Depends on how the cards implement HDMI. Intel cards notably have a DP->HDMI converter chip on-board requiring no software-side support for HDMI.