PowerDevil on KDE 4.2 does not recognize CPU scaling capability on Vostro 1500

[Michael Marley]

Binary package hint: kdebase

Ever since the update to KDE 4.2 Final on Kubuntu 9.04 64-bit, the PowerDevil configuration in the System Settings program does not realize that my system's CPU supports frequency scaling. It simply says that scaling is not available, and does not offer any of the scaling profiles. Frequency scaling does actually work, as I confirmed with Intel PowerTOP. My laptop is a Dell Vostro 1500 with Intel Core 2 Duo T7250.

[Jonas Pedersen (jonasped)]

I can confirm this issue. It used to work with RC releases of KDE 4.2. I am using a Lenovo T500 laptop. It contains a Intel(R) Core(TM)2 Duo P8600 CPU.

[Michael Marley (mamarley)]

This is definitely a regression, then.

[Fabien Meinnier (xenon341)]

Same problem with Toshiba X200 (Kubuntu 9.04 Alpha 4, AMD64 version. (C2D T7300, worked on Intrepid Ibex)

[pagesailor (pagesailor)]

I installed cpufrequtils, and now it works. Give it a try.

[pagesailor (pagesailor)]

Oh, I forget to mention, I'm using Intrepid, scaling stopped working after I uninstalled powernowd. So it seems powerdevil actually needs a scaling governor.

[Michael Marley (mamarley)]

I am running powernowd already, and this bug has to do with KDE4.2, not Intrepid's KDE4.1.

[pagesailor (pagesailor)]

I'm using KDE4.2 too, upgraded from kubuntu-experimental. Maybe it has nothing to do with powernowd, but installing cpufrequtils seems like solved it for me. It wouldn't hurt to give it a try.

[pagesailor (pagesailor)]

I looked into this in a bit greater detail, and it seems like this happens when a cpu frequency info module (acpi_cpufreq) isn't loaded into the kernel. It looks like Powerdevil gets the scaling info from Solid, which gets it from HAL, which gets it from acpi_cpufreq (correct me if I'm wrong). Installing cpufrequtils probably worked for me because it loads this module on system startup. Can anyone confirm this? (It only worked for me if I loaded the module BEFORE powerdevil started.)

[Michael Marley (mamarley)]

After the latest updates in Jaunty, this appears to be fixed.

BTW, acpi_cpufreq loads automatically in Jaunty.

[Jonas Pedersen (jonasped)]

I can confirm this is fixed with latest Jaunty updates. Marking bug as invalid.

[Mackenzie Morgan (maco.m)]

That'd be "Fix Released" not "Invalid"