Quick reminder on the likely reason why Valve's New Steam Machine only supports #HDMI 2.0:

""At this time an open source HDMI 2.1 implementation is not possible without running afoul of the HDMI Forum requirements.""

This is what Alex Deucher, the maintainer of the amdgpu #kernel driver, said one and a half years ago here:

gitlab.freedesktop.org/drm/amd…

And from the ticket it looks like the problem remains.

See also Alex's earlier comment from early 2021 in the ticket:

gitlab.freedesktop.org/drm/amd…

""HDMI 2.1 is not available on #Linux due to the HDMI Forum.""

#LinuxKernel #Valve #SteamMachine