LM_Sensors Finally Gets Better Intel CPU Support

While the Linux hardware compatibility of modern processors and motherboards have normally been spot-on, as talked about in our many reviews, one of the areas that still causes annoyances with modern hardware can be the hardware sensors support. For motherboards this commonly means being able to monitor sensors for the temperatures, fan speeds, voltages. For the CPUs, their integrated temperature sensor(s) also aren't commonly supported on just-released Intel and AMD products.

For those with newer Intel CPUs, there is good news as new patches have been posted over the night that enable the LM_Sensors coretemp kernel module to support more modern chips. The newest Intel Core 2 Duo and Core 2 Quad CPUs along with those from the Nehalem and Westmere families have been tested with this code. The Atom N270 has also been tested, but unfortunately its value is currently off.

The first published patch removes the conditional checks for seeing if a thermal sensor can be found on the die of processors such as the Pentium M, Core 2 Duo 65nm, Core 2 Solo 65nm, Penryn, Nehalem, and Lynnfield. Instead the driver now checks a CPUID instruction (CPUID.06H.EAX[0]) to determine if thermal sensors are available. This should hopefully make the driver more forward-compatible with new Intel processors in the future. Another published patch now reads the TjMax value from the CPU itself via an MSR.

This Intel Linux sensor work was done by Intel's Huaxu Wan and Carsten Emde of the Open-Source Automation Development Lab eG. The patches can be found on the LM_Sensors mailing list.