Linux 7.4 adds chipset temperature monitoring for AMD 600-series boards

Linux 7.4 adds the ability to monitor chipset temperatures on AMD 600-series motherboards, including X670, X670E, and B650 models. Reports say the necessary patch is also tagged for backporting to the Linux 7.2 and 7.3 stable series. The update works by adding these chipsets to the existing prom21-xhci driver, which previously only included 800-series device IDs.

Image: Hardware Busters

According to kernel documentation, the driver reads the temperature of the integrated USB controller within the Promontory 21 die rather than a dedicated chipset diode. This reading serves as a proxy for the chipset temperature. On X670E boards that use two chips, users may see two separate sensors. To enable this, the SENSORS_PROM21_XHCI option must be used.

The temperature conversion uses the formula raw * 0.9066 - 78.624. Because this formula was derived from observed data rather than an official AMD specification, the kernel documentation advises caution with absolute numbers. The driver does not coordinate with ACPI or firmware and will not wake a suspended controller to perform a reading.