I recently discovered my Laptops 2.26Ghz processor was always running at 800Mhz. So I installed cpufreq, only to
find the following:
tc@box:~$ cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.27 GHz
available frequency steps: 2.27 GHz, 1.87 GHz, 1.60 GHz, 1.33 GHz, 1.07 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 800 MHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
After some poking around I found this:
tc@box:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/bios_limit
800000
Some Googling turned up:
https://bugzilla.redhat.com/show_bug.cgi?id=618149https://bugzilla.kernel.org/show_bug.cgi?id=16362The solution was to use the following boot code:
processor.ignore_ppc=1
The laptop now adjusts the CPU frequency as required.