Re: kern/58372: Temperature reading broken on Intel Core 2 Duo E6300 (patch provided)

["David H. Gutteridge" <david%gutteridge.ca@localhost>]

The following reply was made to PR kern/58372; it has been noted by GNATS.

From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/58372: Temperature reading broken on Intel Core 2 Duo E6300
 (patch provided)
Date: Thu, 27 Jun 2024 12:18:31 -0400

 A couple of things. The zero value assignment itself was a regression
 that has since been addressed differently and pulled up to the 9 and 10
 branches. It still doesn't address that we can't correctly read the
 value in some cases, it just moves the default back to 100 as it was
 previously.
 
 74 seems oddly low. I realize that's what's in the table you referenced
 but I would expect it to be a bit higher. That table lists T case max,
 which is not the same as T junction max, as I read Intel's definitions.
 If you look at page 72 in the datasheet, you'll see under "THERMTRIP#"
 it says "the processor will automatically shut down when the silicon
 has reached a temperature approximately 20 °C above the maximum TC.
 Assertion of THERMTRIP# (Thermal Trip) indicates the processor junction
 temperature has reached a level beyond where permanent silicon damage
 may occur." So my interpretation of that is TjMax is somewhere between
 74 and 94, but not clearly defined. (I could be quite wrong, this is
 not an area I've delved into much.)
 
 Regards,
 
 Dave
 
 PS my reference for T junction vs. T case is:
 https://www.intel.com/content/www/us/en/support/articles/000005597/processors.html