If the bios controls the fan, why does the fan run differently if I work with Vista (usually I work only with Slackware)?
Anyway, I tried to recompile the kernel with the same config-generic-smp. I changed nothing (except built-in ext3 support).
Curiously it worked once (variable temperature, 45-50 C, variable fan speed...). No more.
. Now steadily 50 C and same speed. If I boot when cpu is cold, the fan works during POST only.
With Vista, cpu fan starts and stops regularly.
dmesg regarding "cooling device":
processor LNXCPU:00: registered as cooling_device0
processor LNXCPU:01: registered as cooling_device1
acpi device:39: registered as cooling_device2