Linux k10temp Driver For AMD CPUs Updated To Better Handle Power/Temp Analysis

As we have been eagerly talking about for the past week, the Linux kernel's k10temp driver was updated for better AMD CPU CCD temperatures and voltage/current reporting. Those improvements have been quickly evolving thanks to the work of the open-source community with AMD still sadly holding the datasheets concerning the power/temperature registers close to their vest. A new version of k10temp was sent out on Wednesday.

As reported earlier this week, these k10temp improvements could land for the upcoming Linux 5.6 but additional testing is needed. While Zen 2 CPUs have been shipping for months, these k10temp improvements are only coming now thanks to HWMON maintainer Guenter Roeck who continues working on this driver in cooperation with the community as AMD currently isn't releasing documentation/datasheets concerning the power/thermal registers or any reference code for that matter... Many Linux desktop users dream of seeing something someday like AMD Ryzen Master coming to Linux.

With the v4 driver improvements it normalizes current calculations but still depends upon some potential per-board scaling to be set in the configuration file of LM-Sensors, makes a clarification, and adds DebugFS support for better debugging/analysis on different CPUs.

Due to the lack of official AMD information to assist in figuring out the correct power/thermal reporting information, the DebugFS data is designed to assist in reading the raw information. Dumped via DebugFS is now the raw thermal and SVI register dumps. The focus is on helping to discover additional sensors on various CPUs and/or for helping to fix problems for buggy information on CPUs. Ideally this shouldn't be needed but due to k10temp still being community-driven without much support from AMD, this DebugFS support should be a big help until AMD steps up to the plate.

If all goes well, these k10temp improvements will make it into Linux 5.6.