Linux 4.21 Will Be Able To Read Hygon Dhyana CPU Temperatures, Adds PowerPC OCC

The "hwmon" hardware monitoring changes for the Linux 4.21 kernel were sent in this past weekend. There isn't any major changes for the vast majority of users, but there is a lot of smaller happenings.

With Linux 4.21, the Hygon Dhyana CPUs are now supported by the k10temp driver for being able to report the CPU core temperatures. The Hygon Dhyana processors as a reminder are the Chinese-manufactured processors that are a facsimile of current-generation AMD Zen/EPYC technology. With Linux 4.20 the initial Hygon Dhyana support was added, which mainly came down to mirroring the existing AMD CPU code paths in the kernel but under the new vendor IDs. The k10temp CPU temperature reporting support didn't make it into 4.20, but it's now in place for 4.21 and is mainly just a matter of adding the new Hygon IDs.

The other sizable addition to hwmon in Linux 4.21 is introducing the PowerPC On-Chip Controller (OCC) driver. This new driver is for reporting various system/processor sensor data from thermal to power metrics. This OCC hardware is present on POWER8/POWER9 processors and will now allow users of these newer IBM POWER platforms to access a lot more data easily from Linux.

The STLM75 temperature sensor is now supported by the LM75 driver, there is power management run-time support for the INA3221 driver, and various other minor fixes and improvements.

More details on these changes via the kernel mailing list.