Linux 4.18 To Report CPU Temps Finally On Stoney & Bristol Ridge

The hardware monitoring "hwmon" updates have been sent in for the just-opened Linux 4.18 kernel merge window while what's interesting this time around are the k10temp driver updates for AMD CPU temperature reporting.

With Linux 4.18, the k10temp kernel driver is now able to report temperatures on Stoney Ridge and Bristol Ridge processors. Stoney Ridge are the 2016 ultra-mobile APUs with Excavator v2 cores and GCN 1.2 graphics. Bristol Ridge as a refresher is the 2016 desktop/mobile APUs like the Athlon X4 970, A12-9800, A10-9700, etc. Only now with the Linux 4.18 kernel is there CPU temperature reporting under Linux for these two year old processors.

Separately, another change to the k10temp driver in Linux 4.18 is support for reporting both the Tctl and Tdie values. Tdie is the die temperature while Tctl is the reported temperature. The Tctl value is used for fan control while Tdie is the real CPU die temperature. On capable CPUs, the driver now reports both values.

Those are the main changes to find this cycle for the HWMON subsystem via this pull request.