from Dominik Brodowski

The current algorithm used by Linux ACPI for passive thermal management has
two shortcomings:

- if increasing the CPU processing power as a thermal situation goes away,
  throttling states are decreased later than performance states. This is
  not wise -- it should be the opposite ordering of going "up".

- only if the ACPI CPUfreq driver is used, performance states are used.
  A generalized approach would offer passive cooling even if the ACPI
  P-States cpufreq driver cannot be used (faulty BIOS, FixedHW access, etc.)