Linux 7.4 merge window brings Steam Frame VR, AMD Zen 6 prep, Apple M4/A18 Pro bring-up

The Linux 7.4 kernel merge window has concluded as the largest in the project's history, with the release expected to become 2026's Long Term Support kernel. The cycle brings substantial hardware enablement including AMD Ryzen Zen 6 client platform support with device ID additions and security mitigation improvements via BTB CTX isolation, initial Apple M4 and A18 Pro SoC device trees, mainline support for Google's Tensor G5 and Pixel 10 smartphones, and basic device tree support for Valve's Steam Frame VR headset.

On the graphics front, AMDGPU now enables HDMI 2.1 by default including VRR/FreeSync and ALLM support, while AMD PerfOpt is enabled by default for improved AI/LLM workload performance on Radeon integrated GPUs. Memory management sees significant optimizations including a boot-time physical allocator speedup from approximately 265 seconds to 50 milliseconds in testing, plus CXL preparations for dynamic capacity scaling. The Intel Xe driver gains vRAM health monitoring and degraded memory handling, and the MSM DRM driver expands to cover new Qualcomm Adreno A830, A845, A850, and X2-85 GPUs.

What changes in Linux 7.4

• CPU/platform support: AMD Zen 6 client and EPYC PML (Page Modification Logging) support added across platform drivers, with BTB CTX isolation enabling less costly security mitigations; initial Apple M4/A18 Pro device trees merged though functionality remains extremely limited.
• Graphics/display: AMDGPU HDMI 2.1 enabled by default with VRR/FreeSync and ALLM support; AMD PerfOpt enabled by default for Radeon iGPU AI/LLM performance; Intel Xe driver adds CPU binds, ULLS on migration queue, and vRAM health checks with degraded memory handling.
• Memory management: Early boot physical allocator optimized from ~265 seconds to ~50 milliseconds in testing; CXL Dynamic Capacity Device preparations allow runtime memory scaling without reboot; new Core MM tree introduced.
• Scheduler and virtualization: Improved scheduling latency for short-slice tasks; random idle CPU selection for equally shallow cores; new steal governor for VM enhancement; Intel Instruction Timeout/VM-Exit with KVM; ARM64 on s390 KVM virtualization for IBM/Arm dual-architecture hardware.
• Mobile and embedded: Google Tensor G5 and Pixel 10 mainline support; Qualcomm Snapdragon X2 laptop support expanded; MSM DRM driver adds Adreno A830, A845, A850, X2-85; new Nintendo Switch 2 controller driver; Steam Frame VR headset basic device tree support.

Why it matters

Linux 7.4's expected LTS status means these hardware enablement changes will define platform support for enterprise distributions, SteamOS, and embedded products through 2029 or beyond. The AMD Zen 6 and Apple Silicon bring-up ensures competitive Linux support for next-generation client hardware at launch, while the Steam Frame VR device tree signals Valve's continued investment in Linux-native VR. For Steam Deck and Linux gaming users, the HDMI 2.1 default enablement finally resolves long-standing VRR limitations on Radeon hardware with high-refresh displays.