Linux 7.4 merge window to bring HDMI 2.1 default for Radeon, Apple M4 DTs, AMD Zen 6 support
The Linux 7.4 kernel merge window is expected to include AMDGPU HDMI 2.1 enabled by default, AMD PerfOpt IOMMU for iGPU AI/LLM performance gains, initial Apple M4 Device Trees, and expanded AMD Zen 6 support.
Summary
With Linux 7.3 nearing release, the 7.4 merge window is set to open with substantial hardware enablement across multiple vendors. AMD Radeon users will see HDMI 2.1 support enabled by default in the AMDGPU driver, including VRR and ALLM. AMD iGPU users stand to gain from the PerfOpt IOMMU feature, which can improve AI/LLM workload performance on prior-generation hardware as well. Intel is preparing for Panther Lake and merging the BFF driver, while Apple M4 and Qualcomm Snapdragon X2 laptops see initial upstreaming efforts. The kernel also drops the Google C Binder driver in favor of the Rust implementation.
What's landing in Linux 7.4
- AMDGPU HDMI 2.1: Enabled by default with VRR and ALLM support, following late-year open-sourcing of related patches
- AMD PerfOpt IOMMU: Default-enabled feature for iGPUs that can yield "big AI/LLM performance improvements" on current and prior-generation hardware
- AMD Zen 6: BTB CTX isolation, RMPOPT optimization, and P-State driver improvements
- AMDXDNA: Device ID added for Ryzen AI Max 400 series (Gorgon Halo) NPU
- Intel: BFF driver merge, Battlemage CPU binds and ULLS on migration queue, vRAM health check with degraded memory handling
- Apple Silicon: Initial Device Trees for M4 and A18 Pro (MacBook Neo); audio support upstreaming; still not end-user ready
- Qualcomm: Snapdragon X2 laptop support continuing to materialize
- Google: Tensor G5 SoC and Pixel 10 mainline support
- File systems: EXT4 IOmap buffered I/O path, large folios for FUSE
- Virtualization: Intel Instruction Timeout (Notify VM Exit) for TDX DoS mitigation; Microsoft para-virtualized IOMMU Hyper-V driver; steal governor
- Code removal: Google C Binder driver replaced by Rust-based Binder driver
Why it matters
The default HDMI 2.1 enablement removes a long-standing friction point for Radeon users with modern displays. The AMD PerfOpt IOMMU change could meaningfully improve local AI inference on widely deployed iGPUs. However, Apple M4 support remains developer-only, continuing the pattern of slow mainline enablement for Apple Silicon.
What to do
- If you use AMD Radeon graphics, update to Linux 7.4 when released to get HDMI 2.1 with VRR and ALLM enabled by default.
- If you run AI/LLM workloads on AMD iGPUs, update to Linux 7.4 for the PerfOpt IOMMU performance improvements.
- If you use Intel Battlemage graphics, update to Linux 7.4 for vRAM health checks and degraded memory handling.
- If you rely on the Google C Binder driver, prepare to switch to the Rust-based Binder driver in Linux 7.4.
Original reference: www.phoronix.com →