Martin Roth has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/35042 )
Change subject: mb/google/kahlee/treeya: Update STAPM parameters for Treeya ......................................................................
Patch Set 4: Code-Review+2
(1 comment)
https://review.coreboot.org/c/coreboot/+/35042/2//COMMIT_MSG Commit Message:
https://review.coreboot.org/c/coreboot/+/35042/2//COMMIT_MSG@9 PS2, Line 9: Tuning stapm percentage from 80 to 68 and time from 250 second : to 90 second make them meet Lenovo temperature spec.
Done
Unfortunately, people outside google and partners can't see the buganizer bugs.
STAPM parameters are decided by measuring the skin temperature of a machine while running a (standardized) heavy workload. The temperature isn't allowed to get too hot in any one area, so thermal spreaders are required to allow cooling across a large area. Unfortunately that adds weight and cost, so it's a trade off.
What the STAPM parameters do is basically restrict how much power can go to the processor in a given amount of time before it has time to cool down. At some point in an ongoing heavy workload, it has to balance how much power the processor gets with how much heat can be dissipated.