AMD Carrizo Power Information To Be Exposed In Linux 4.3

The hwmon subsystem update was another early pull request for the Linux 4.3 kernel.

New hardware monitoring support in Linux 4.3 includes support for the LTM4675, LTC3886, LTC2980, LTM2987, LTC2975,
LTC3887, LTC3882, MAX20751, ADM1293, ADM1294, IT8732F, F81866, and F71868 ASICs.

The change likely of most interest to Phoronix readers though for hwmon in Linux 4.3 is Carrizo support within the fam15h_power driver. The fam15h_power driver has been around for a while now and exposes the power information of AMD Family 15h processors under Linux. The driver is supposed to be able to expose the power consumption (in Watts) for the processor, the maximum possible power consumption, and the current consumption. However, last time I tried out this driver what seemed like years ago with some earlier Bulldozer parts, the reported values were wildly inaccurate.

With Linux 4.3, this driver will now report Carrizo power metrics. Once I get my hands on an AMD Carrizo system, I'll see how well the driver works today with the latest AMD hardware. The hwmon feature pull request for Linux 4.3 can be read on the kernel mailing list.