AMD 600 Series chipset temperature monitoring lands in Linux 7.4 with back-ports

The Linux 7.4 kernel has gained support for temperature sensors on AMD 600 Series chipsets, which launched alongside AMD's Ryzen 7000 series processors on the AM5 socket. This capability arrives through a patch adding the missing PCI device IDs to the xhci-pci-prom21 driver that was introduced earlier this year in Linux 7.2. That original driver, developed using OpenAI Codex GPT-5.5, only included device IDs for the newer AMD 800 Series chipsets, leaving 600 Series motherboard owners without thermal monitoring.

The fix has been upstreamed in Linux 7.4 and is marked for back-porting to the v7.2 and v7.3 stable kernel series. No other driver modifications were required beyond adding the correct PCI identifiers, as the underlying temperature-reading infrastructure for the Promontory 21 xHCI controllers was already in place.

Driver architecture and merge details

• Promontory 21 chipset family: The xhci-pci-prom21 driver targets temperature sensors embedded in the xHCI USB controllers found on both AMD 600 Series and 800 Series chipsets for AM5 platforms.
• Linux 7.2 limitation: The original driver upstreamed in Linux 7.2 only registered PCI device IDs for 800 Series chipsets, inadvertently excluding 600 Series hardware from thermal monitoring despite identical underlying silicon.
• Minimal patch scope: The Linux 7.4 fix requires only additional PCI ID entries with no changes to the driver's temperature-reading logic or sysfs interface.
• Merge path: The patch entered mainline through the USB subsystem pull request during the Linux 7.4 merge window, reflecting the driver's location within the xHCI PCI driver hierarchy.
• Back-porting plan: The change is explicitly marked for stable back-porting to Linux v7.2 and v7.3, extending support to users on earlier kernel versions without requiring a full distribution upgrade.

Why it matters

For Linux desktop users and system administrators running Ryzen 7000 systems on B650, X670, and other 600 Series motherboards, this closes a notable gap in hardware monitoring capabilities that has persisted since the platform's 2022 launch. The stable back-ports mean distributions shipping Linux 7.2 or 7.3 can incorporate the fix without waiting for a major kernel cycle, improving thermal visibility for workstation builds and headless servers where temperature-driven fan control and alerting depend on accurate chipset readings.