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."