It Doesn't Look Like A Ryzen/EPYC Thermal Driver Will Make It For Linux 4.14

While the Ryzen CPUs have been available for a few months now and the higher-wattage Threadripper and EPYC processors are now available too, the Linux thermal driver remains missing in action and it's looking less likely that it will materialize for Linux 4.14.

The Linux 4.14 merge window should open this weekend, unless the Linux 4.13 cycle is unexpectedly stretched by an additional week.

The various subsystem maintainers are prepping their "-next" trees for Linux 4.14 merging, including hwmon maintainer Guenter Roeck. Unfortunately, there still is no Zen/Ryzen/Threadripper/EPYC thermal driver in the tree.

A glance in hwmon-next shows the material queued so far, including a Lantiq cpu temperature sensor support (used by the XRX200), but nothing on the AMD front.

There's also been no posting of any driver for review on the kernel mailing list yet. I'm still holding out hope we could maybe see one arrive for Linux 4.14, but last I heard from AMD contacts is they were still getting the necessary documentation out there.

For most users a Zen thermal driver isn't necessary unless you plan on overclocking your system, are concerned about the air cooling with Threadripper, compare cooling solutions (in fact, one of the reasons I've been waiting for this driver), or want to feel otherwise safe while running especially EPYC/Threadripper. Aside from the missing thermal sensor support, the Ryzen/Threadripper support has been working out well on Linux. It would be nice to see it too for Linux 4.14 considering this is a Long Term Support (LTS) kernel release likely to be used by Ubuntu 18.04 among other early 2018 Linux distributions.