Linux 7.4 will enable HDMI 2.1 by default in the AMDGPU driver, with FreeSync, VRR and ALLM support included. The AMD feature pull request went to DRM-Next on September 10.

This closes one of the longest-running grievances in Linux graphics.

What was blocking it

The HDMI Forum rejected an open-source HDMI 2.1 implementation for the AMDGPU driver, and held that position for years.

The practical result was absurd from a user’s point of view. You could buy an AMD card and a HDMI 2.1 display, and Linux would drive it at HDMI 2.0 rates. High refresh rates at 4K, and 8K at all, were unavailable over HDMI, while the same card handled them over DisplayPort without issue. The hardware was capable, the driver could not legally expose it.

The standard workaround was DisplayPort, which is fine on a monitor and not an option on a television. For anyone running a Linux machine into a living-room TV, this was the whole problem.

Something shifted in 2026. Patches began appearing, and the change is widely speculated to involve Valve, though that has not been confirmed publicly. Valve having both a large commercial interest in Linux gaming on televisions and the standing to negotiate makes the speculation plausible rather than established.

What has landed, and when

Kernel	What arrived
7.2	HDMI 2.1 FRL (Fixed Rate Link), disabled by default
7.4	FreeSync, VRR, ALLM, and FRL turned on by default

FRL is the signalling change that carries the higher bandwidth, and it is what makes 4K at high refresh possible over HDMI.

VRR and FreeSync let the display refresh in step with the frame rate rather than on a fixed clock, which removes tearing and the stutter you get when frame time and refresh interval drift apart.

ALLM, Auto Low Latency Mode, tells a TV to switch itself into game mode automatically. Televisions apply heavy post-processing by default and that processing costs latency. ALLM means you stop having to find the right picture mode by hand every time.

FRL was deliberately held disabled until the VRR work was ready, to avoid shipping a half-finished path that regressed working setups. Turning it on now is the signal that AMD considers the implementation complete.

Also in the pull

Support work for the GFX12.1 graphics engine, DCN 6 display engine, and SMU 15 power management IP, which is the usual pattern of enabling next-generation hardware a cycle or two before it appears.

When you get it

The 7.4 merge window opens in the second half of October, after 7.3 ships. Linux 7.4 itself is expected around the very end of 2026 or early January.

Distribution timing then adds its own delay. Ubuntu 26.10 is shipping on 7.3, so this reaches Ubuntu users in 27.04 unless they run a mainline kernel themselves. Rolling distributions will have it sooner.

# what link rate is in use
sudo cat /sys/kernel/debug/dri/0/amdgpu_dm_capabilities 2>/dev/null

# is VRR active on your connector
xrandr --props | grep -i vrr        # X11
# on Wayland, check your compositor settings

Who benefits

Anyone running an AMD GPU into a modern television, which is the case this was always about. Living-room machines, couch gaming, and Steam Deck-adjacent setups driving a large panel.

If your display is a DisplayPort monitor, you have had these capabilities for years and nothing changes. That asymmetry was the frustrating part: the limitation was never technical.