Valve Trying to Unblock Open-Source HDMI 2.1 Support on Steam Machine

Valve is reportedly attempting to persuade the HDMI Forum—the consortium responsible for HDMI development—to allow open-source support for HDMI 2.1 on Linux, enabling the standard to function without restrictions on SteamOS. When Valve launched its Steam Machine, it was listed with HDMI 2.0 support, which seemed an odd choice given that HDMI 2.1 had become more prevalent. However, the Steam Machine does indeed feature an HDMI 2.1 port, but due to the HDMI Forum’s stance against open implementations, Valve officially listed it as supporting the older HDMI 2.0.

According to an interview with Ars Technica, Valve is now trying to clarify this situation. The company has been “working on trying to unblock things there” to gain official support and approval for HDMI 2.1 from the HDMI Forum. In early 2024, AMD proposed incorporating key HDMI 2.1 features, such as 4K at 120 Hz and 5K at 240 Hz, into their open-source Linux graphics driver, AMDGPU. However, the HDMI Forum quickly criticized the proposal, and AMD stated: “The HDMI Forum has rejected our proposal, unfortunately. At this time, an open-source HDMI 2.1 implementation is not possible without violating HDMI Forum requirements.”

Given its use of AMD hardware and experiences, Valve is now attempting to engage with the HDMI Forum leadership to gain approval for open-source implementation. AMD had previously invested engineering resources over several months to develop the necessary code internally before making it public, and Valve has likely followed a similar approach. Since the HDMI Forum released the HDMI 2.2 standard in June of this year, there might be an opportunity for the approval of an open-source HDMI 2.1 implementation, as it is now a generation older. SteamOS uses open-source AMD GPU driver components because Steam Machine runs on an AMD RDNA 3.5 GPU. As a result, any HDMI 2.1 features for AMD GPU users on Linux will rely on the good will of the HDMI Forum.