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Suggestions wanted



While looking at including ADT7490 support in my recently-committed dbcool driver, I discovered that this beast implements a rather odd sort of sensor!

There's new PECI (Intel's "Platform Environment Control Interface") set of four sensors. This is actually a communications path to the CPU which provides the actual sensor values. Unfortunately, the spec calls for the PECI temp sensors to be reported as a _relative_ temperature, measured in degrees C. The values are always negative (less than 0), and are relative to a CPU-specific Tcc thermal control circuit activation temperature. There appears to be no way to access the value of Tcc, so it's apparently impossible to convert the relative readings to absolute ones.

I could just display these values as absolute temperatures, and they would mostly make sense when displayed in degreesC. But if the user were to convert to degrees F (with envstat -f) the values would be off by 32F.

Alternatively, I could implement a new sensor type in sysmon_envsys(9) and envstat(8) for relative temperature sensors.

Or I could just ignore these sensors completely.

Are there any other options?

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