CPU Power mng refuses to come back to normal after sleep (Toshiba Satellite 2250CDT)
 

Hi

I just found this (very old) laptop (Toshiba Satellite 2250CDT). Seems to be almost fully compatible with Linux, even the Winmodem... But I have a very very strange and disturbing bug about ACPI.

This laptop support Power Management (Processor State: C1, C2) to save battery. The processor is a 600 Mhz Celeron (Coppermine).
cat /proc/cpuinfo give it right and x86info -mhz too. So it is obliviously a 600 mhz. Usually, the /proc/acpi/processor/CPU0/power shows me the laptop use the "C2" power state. And it works fine.

Everything is fine, until the laptop enter sleep mode (echo 1 > /proc/acpi/sleep or echo stanby > /sys/power/state).
When it come back, everything seems fine but... the computer is damn slow. cpuinfo show no change, BUT /proc/acpi/processor/CPU0/power will now shows me that the laptop switched to "C1" state...
If I run x86info -mhz now, I get a result of... 80MHZ!!! Only!
Looks like my laptop switch his CPU power to 80mhz in order to save power but NEVER get it back to normal... If you wonder, 80mhz is slow as hell.



I'm looking for a way to force the processor to switch back to C2 state (since C1 seems to be buggy) or at least to shut this feature down and so to prevent the laptop to using this tricks to save power...
No module or such thing seems to prevent the laptop from switching (I unloaded almost everything to try). I also tried to edit kernel code to avoid power management from activating, but it seems to be BIOS related, because it switch state anyways...

Any idea?
Any help, even dumb idea is welcome :)