Further expanded AMD HDMI 2.1 support is coming to Linux now with FRL and DSC

Good news for Linux gamers and the upcoming Steam Machine, as it appears the AMD GPU kernel drivers are expanding their HDMI 2.1 support even further.

Previously we had patches submitted to the Linux kernel to enable HDMI FRL (Fixed Rate Link) support, but these patches have been revised with version 3 now also bringing DSC (Display Stream Compression). Together, if approved and accepted into the Linux kernel, they should really help AMD HDMI supporter higher resolutions and refresh rates which has been quite the missing link for AMD + Linux on the open source Mesa drivers.

From the kernel mailing list:

This patch series adds HDMI FRL and FRL DSC support to the amdgpu display driver.

This work passed a representative subset of HDMI compliance and a full compliance run on this branch is in the works. We don't expect the full run to show any failures since it passes in other environments.

Thanks to Siqueira who prepared this work a couple years back and unfortunately didn't manage to send them while he was still working at AMD.

Thanks to Jerry who has been making this code solid on Linux and running the compliance tests.

The first patch in the series isn't related to HDMI 2.1 but included here because it moved the code around some key bits of the HDMI 2.1 stuff around too much. It will land with the next DC Patch series.

v3:
- Add missing DML2 bits
- Merged register headers to asdn and removed from patchset

v2:
- Add missing function pointers on DCN 3.x
- Add DSC

This will be a really great boost for Linux (and not just for gaming) if the patches get fully accepted, to see in a future Linux kernel release which would most likely be kernel 7.2 since 7.1 is already in the release candidate stage. So we might see this actually available in the second half of 2026.