Linux 7.4 merge window brings HDMI 2.1 default for Radeon, Apple M4 DTs, AMD PerfOpt
The Linux 7.4 kernel merge window is opening with AMDGPU enabling HDMI 2.1 by default, AMD PerfOpt IOMMU for iGPU AI/LLM workloads, initial Apple M4 device trees, and Google Tensor G5 mainlining.
Summary
Linux 7.4 development is beginning as 7.3 nears release. The AMDGPU driver will enable HDMI 2.1 by default now that VRR and ALLM support is complete. AMD's PerfOpt IOMMU feature, enabled by default, promises significant AI and LLM performance gains on AMD integrated GPUs including older hardware. Initial device tree support for Apple M4 and A18 Pro is landing, though Apple Silicon remains non-functional for end users. The kernel will also mainline Google Tensor G5 and Pixel 10 support, add more Zen 6 features, and introduce Intel Instruction Timeout for TDX VM security.
What's landing in Linux 7.4
- AMDGPU HDMI 2.1: Enabled by default with VRR and ALLM support now complete; patches were open-sourced later this year
- AMD PerfOpt IOMMU: Default-on feature for AMD iGPUs yielding "big AI/LLM performance improvements" on prior generation hardware too
- AMD Zen 6: BTB CTX isolation, RMPOPT optimization, and P-State driver improvements
- AMDXDNA: Adds missing device ID for Ryzen AI Max 400 series (Gorgon Halo) NPU
- Intel graphics: Battlemage CPU binds and ULLS on migration queue; vRAM health check and degraded memory handling; BFF driver merged; Rugged Panther Lake preparations
- NVIDIA: Continued work on Nova driver
- Qualcomm: Snapdragon X2 laptop upstreaming continues
- Apple Silicon: Initial M4 and A18 Pro Device Trees for MacBook Neo; audio support upstreaming; still not end-user usable
- Google: Tensor G5 SoC and Pixel 10 mainline support
- Hardware misc: Raspberry Pi 10-inch Touch Display 2, laptop and handheld gaming device improvements
- 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
- Networking: Nebula Matrix driver upstreamed
- Code changes: Google C Binder driver removed in favor of Rust-based Binder; kernel taint for fuzzing-bot era; MM optimizations; faster single-file opening; Zstd improvements; AVX-512 optimized xor_gen; kernel build time speedups beginning
Why it matters
The AMDGPU HDMI 2.1 default finally brings modern display features to Radeon users without manual enablement, while AMD PerfOpt IOMMU could significantly improve local AI inference performance on widely deployed iGPUs. However, Apple M4 support remains developer-only for now.
What to do
- Wait for Linux 7.4 to reach stable release around end of December before upgrading.
- If you use AMD integrated GPUs, update to Linux 7.4 when available for AI/LLM performance gains via the default-on AMD PerfOpt IOMMU feature.
- If you have modern Radeon graphics, update to Linux 7.4 when available for default HDMI 2.1 support with VRR and ALLM.
Original reference: www.phoronix.com →