Linux 6.5-rc4 Fixes Support For Reporting Negative Temperatures On AMD Industrial CPUs

Going back to May I wrote about AMD's "k10temp" Linux temperature driver being updated to handle negative temperature readings and now finally merged on Friday as a fix ahead of Linux 6.5-rc4 is a change to that open-source driver for properly displaying negative temperatures.

Since May that negative temperature support has been revised from originally just dropping "less than zero" checks to now selectively only allowing the negative range for AMD industrial CPUs. In particular, the support is focused on the AMD EPYC Embedded 3255 processor that has a supported temperature range from -40 Celsius to 105 Celsius.

This negative temperature support isn't for satisfying liquid nitrogen overclockers or any exotic enthusiast use-cases but for industrial Linux users deploying the AMD EPYC Embedded 3255 in harsh (very cold) environments. The EPYC Embedded 3255 is an eight core Zen processor rated for 65 Watts with a 2.5GHz base frequency and 3.1GHz boost frequency.

This negative temperature support for k10temp can be found via this Git merge to mainline for Linux 6.5-rc4 and ahead of next month's v6.5 stable debut.