AMD Readies Full Open-Source HDMI 2.1 Support for Linux

If readers recall, AMD has been trying to get the HDMI Forum, the governing body behind the development of the HDMI standard, to approve open-source HDMI 2.1 support on Linux but faced strong rejection. However, today the situation appears to be different. An AMD Linux developer hinted that the company is preparing full HDMI 2.1 support for the AMDGPU driver, bringing a complete open-source implementation after years of work. Helping this effort is Valve, whose Steam Machine runs on the SteamOS Linux operating system and uses AMD graphics. Late last year, we reported that Valve was reportedly attempting to persuade the HDMI Forum to approve AMD’s efforts to bring this implementation to the open-source Linux stack, but we haven’t received an update since.

Today, the situation looks a bit different as AMD has submitted the first set of Linux kernel patches, focusing on the Fixed Rate Link (FRL) feature, exclusive to the HDMI 2.1 standard. This feature enables higher bandwidth over the port, effectively supporting 4K at 120 Hz and 5K at 240 Hz resolutions on AMD GPUs running Linux-based operating systems. As these resolutions require higher data bandwidth, it is necessary to use the newer HDMI 2.1 standard over the currently supported HDMI 2.0 in AMDGPU open-source graphics drivers.

A significant negotiation took place late last year on Valve’s side. Given its use of AMD hardware and experience, Valve attempted to engage with the HDMI Forum leadership to gain approval for the open-source implementation. AMD had previously invested engineering resources over several months to develop the necessary code internally before making it public in 2024. However, the HDMI Forum responded strongly, claiming that the open-source implementation is impossible without violating their requirements for fair use. Valve’s SteamOS uses open-source AMD GPU driver components because the Steam Machine runs on an AMD RDNA 3 GPU, and the company’s negotiations seem to have done their part.