Ondemand profile cannot be selected for processor frequency scaling

[Steve Blamey]

Binary package hint: acpi-support

Trying to set 'Ondemand' profile for processor freq. scaling. Using 'CPU Frequency Scaling Monitor 2.28.0' or directly at /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor Ondemand is not set but remains at Performance.

In fact, it seems that only Powersave or Performance can be set on my system. Selecting Ondemand or Conservative results in Performance being set.

ProblemType: Bug
Architecture: i386
CheckboxSubmission: f5d9d4f5376d4406dcf08158d79e32d0
CheckboxSystem: efd05939b08abfe86caa44c3820f8e56
Date: Wed Oct 7 14:56:16 2009
DistroRelease: Ubuntu 9.10
Package: acpi-support 0.127
ProcEnviron:
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-12.40-generic
SourcePackage: acpi-support
Uname: Linux 2.6.31-12-generic i686

[Steve Langasek (vorlon)]

Nothing to do with acpi-support; this is either a kernel bug or a hardware limitation. Reassigning.

[Steve Blamey (fedorus-deactivatedaccount)]

A regression then. Ondemand worked in 9.04 on this machine.

[Steve Blamey (fedorus-deactivatedaccount)]

Here is the error from the kernel.log

kernel: [ 108.779658] ondemand governor failed, too long transition latency of HW, fallback to performance governor

[Steve Blamey (fedorus-deactivatedaccount)]

I installed powernowd and that is able to switch my processor between the two available frequencies as required.

[Steve Blamey (fedorus-deactivatedaccount)]

Possibly related to Bug #223812 ?
https://bugs.launchpad.net/ubuntu/+source/powernowd/+bug/223812

[AceLan Kao (acelankao)]

So, does your problem solved by installing powernowd?

[Steve Blamey (fedorus-deactivatedaccount)]

I have now been able to do a clean install of Karmic Beta from .iso and installed all the latest patches. The Ondemand governor now works as expected without having to install powernowd.

Previously I had done an dist upgrade from 9.04, so something must have been missed at that point.

[AceLan Kao (acelankao)]

Really good to hear that, so I'm going to close this bug. Thanks for your kindly report.