Hi Arjan,
--
it seems that the changes inside processor module have bitten another user, see relevant thread at archlinux bugtracker:
http://bugs.archlinux.org/task/17771
It can be summarised with the following quote:
I've tested jimis's suggestion about booting with init=/bin/sh and later modprobing next modules.
I confirm that module called "processor" in any kernel26 2.6.32.* is a root problem of high power consumption.
Here's output of modprobing it:
ACPI: SSDT 000000003f6d94fb 00238 (v01 PmRef Cpu0Ist 000003000 INTL 20050624)
ACPI: SSDT 000000003f6d8e8c 005EA (v01 PmRef Cpu0Cst 000003001 INTL 20050624)
Marking TSC unstable due to TSC halts in idle
processor LNXCPU:00: registered as cooling_device0
ACPI: SSDT 000000003f6d9733 000C8(v01 PmRef Cpu1Ist 000003000 INTL 20050624)
ACPI: SSDT 00000000376d9476 00085 (v01 PmRef Cpu1Cst 000003000 INTL 20050624)
Swtiching to clocksource hpet
processor LNXCPU:01: registered as cooling_device1
As I understand, in his case the C3 state is unstable and exits immediately. I have asked him to post the dmidecode output so you can put him on the exception list too. However I now believe that more and more users will be facing the same problem, it's not something you find easily, especially on desktop machines! What do you think?
Thanks,
Dimitris