AMD submits HDMI 2.1 FRL patches for open-source Linux driver

AMD has submitted a series of Linux kernel patches to the AMDGPU driver that introduce support for the HDMI 2.1 Fixed Rate Link (FRL) feature. The move follows years of rejection from the HDMI Forum regarding open-source implementations of the standard. This initial support enables higher bandwidth for Radeon GPUs on Linux, supporting resolutions such as 4K at 120Hz and 5K at 240Hz.

As noted by AMD Linux engineer Harry Wentland (via Phoronix), AMD had developed the code in 2024. Still, the HDMI Forum previously blocked its release, citing concerns about exposing proprietary intellectual property in open-source stacks. 

The current patch set submitted by Wentland implements FRL signalling, replacing the legacy TMDS mechanism used in HDMI 2.0. While FRL support has passed representative compliance testing, other HDMI 2.1 features such as Display Stream Compression (DSC) and Variable Refresh Rate (VRR) are currently in testing and will be submitted in future updates.

The patches are now under review on the Linux kernel mailing list. If approved, the code is expected to be integrated into the Linux v7.2 kernel release. This implementation would allow Linux users to access the full 48Gbps bandwidth of the HDMI 2.1 standard without relying on closed-source firmware or third-party workarounds.

KitGuru says: With the Steam Machine supposedly right around the corner, this update comes right on time, allowing the console to be on par with equivalent Windows systems.

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