Comment 8 for bug 177076

Someone posted the following on the T4220 wiki page ( https://help.ubuntu.com/community/T4220 ):

"Actually the problem lies in the ACPI-DSDT. The Linux-Kernel reports to be WIN-Vista-compatible, therefore the DSDT tries to load an additional piece of AML code in this case, which is not ACPI-compatible. After this bug there is a missing temperature offset, an the kernel starts to thermo-throttle CPU. The incomplete load of the vista table is also the reason for the missing symbols in the button-events.

      2 Solutions are possible:

      switch off Vista compatibility in ACPI (acpi_osi="!Windows 2006")

      use modified DSDT: http://ginkel2.boerde.de/Lifebook_4220/lt4220.tgz "

I've tested the acpi_osi= kernel option and it appear to solve my cpu scaling issues, so this bug can probably be marked closed.