AMDGPU Gets HDMI 2.1 by Default in Linux Kernel 7.4

For years the open-source AMDGPU driver in the Linux kernel couldn't gain HDMI 2.1 support: the HDMI Forum refused to allow an open implementation of the standard. Earlier this year, however, the situation changed — by widespread account, not without a hand from Valve — and the relevant patches began to appear in the driver. With the Linux 7.4 development cycle, the bulk of this work will be in place and enabled by default.

How the work progressed

In early May, HDMI 2.1 FRL (Fixed Rate Link) patches showed up for AMDGPU, delivering higher resolutions and refresh rates over HDMI. FRL support landed in the Linux 7.2 kernel, after which other HDMI 2.1-related patches were published as well. For Linux 7.4, the expectation is that all of this work will be accepted, or at least a significant portion of it.

What's in the fresh pull request

The day before, a new pull request enabling AMDGPU features for Linux 7.4 was sent to the DRM-Next branch. It brings support for FreeSync, VRR and ALLM over HDMI 2.1. Auto Low Latency Mode (ALLM) reduces latency in games on compatible monitors and TVs, while VRR and FreeSync had long been awaited in the mainline kernel — first and foremost by gamers.

In addition, FRL for HDMI itself is being enabled by default in Linux 7.4. The code was initially disabled until variable refresh rate support was ready, in order to avoid possible regressions on users' devices.

The same pull request also brings other new features: updates for the upcoming AMD GFX12.1 graphics engine, the DCN 6 display engine and the SMU 15 block, as well as a number of fixes.

When to expect it

The Linux 7.4 merge window will open in the second half of October — the exact date depends on how ready the stable Linux 7.3 release is. The 7.4 release itself could arrive at the very end of 2026 or already in early January: the timing will be determined by how the v7.3 and v7.4 cycles go in today's patch-heavy world, fired up by the AI wave. Either way, the Phoronix author calls the assembled HDMI 2.1 patches for AMDGPU a wonderful Christmas gift for Linux enthusiasts and gaming fans.

Source: Phoronix