Comment 7 for bug 106447

Revision history for this message
zekard (vdumitrean) wrote : Re: acpi_cpufreq detects intel e6400 with 600 to 800 MHz

I figured out a work around for this bug which i have posted on the ubuntu forums:
http://ubuntuforums.org/showthread.php?p=2719839#post2719839

Step 1: Remove Userspace Scaling Software
Code:

sudo apt-get remove powernowd

Step 2: Restart
Acpi_cpufreq should no longer be loaded on startup and the processor(s) should be clocked at their full speed but without scaling support.

Step 3: Manually load your CPU module
I did
Code:

sudo modprobe acpi-cpufreq

Step 4: Load Scaling Modules

I was only interested in ondemand, but load the one(s) you need.

Code:

sudo modprobe cpufreq_ondemand

(others)

Code:

sudo modprobe cpufreq_conservative
sudo modprobe cpufreq_powersave
sudo modprobe cpufreq_stats
sudo modprobe cpufreq_userspace

Step 5: Testing/Configuration

Show Available Governors
Code:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

Select the governor you desire like so
Code:

sudo -s
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Step 6: Load Modules at Boot
Append your selected modules to the end of /etc/modules
Code:

[Step 3 module]
[Modules from Step 4]

Mine was
Code:

acpi-cpufreq
cpufreq_ondemand

Step 7: Configure Modules at Boot
This step needs to be done in order for the modules to retain your settings.
Make sure you have sysfsutils installed
Code:

sudo apt-get install sysfsutils

Then add the following lines to /etc/sysfs.conf
Code:

devices/system/cpu/cpu0/cpufreq/scaling_governor=ondemand
devices/system/cpu/cpu1/cpufreq/scaling_governor=ondemand

(If you have only one cpu then only the first line would apply)

Step 8: Reboot and enjoy
Hopefully everything should work now.