Right driver for cpufreq

Satish Balay balay at fastmail.fm
Tue Oct 26 21:35:08 UTC 2004


On Tue, 26 Oct 2004, Mitko Haralanov wrote:

> Hi, I just installed Fedora Core 2 on my Dell Latitute C800 laptop and I
> having trouble getting the cpu frequency scaling to work. The
> /proc/cpuinfo file shows the cpu as:
> 
> processor       : 0
> vendor_id       : GenuineIntel
> cpu family      : 6
> model           : 8
> model name      : Pentium III (Coppermine)
> stepping        : 10
> cpu MHz         : 997.943
> 
> however, I can't seem to find the driver that I have to use. I have
> tried all the drivers in
> /lib/modules/2.6.8-1.521/kernel/arch/i386/kernel/cpu/cpufreq/ and none
> of the load.
> 
> I would really appreciate any help since I have to go on a trip and I
> will need to use the laptop but under current setup, the battery last
> about 5 seconds.

Don't remember all the details about FC2, but the speedstep driver is
compiled the kernel - (hence fewer listings in
/lib/modules/2.6.8-1.521/kernel/arch/i386/kernel/cpu/cpufreq than in
FC1 kernel) - and it gets detected automatically (FC1 requires
'modprobe speedstep-centrino')

I had briefly used this on a thinkpad with Pentium-M & speedstep was
working fine.

A couple of things to verify.

- Your CPU is 1GHz and always at that speed?
- do you have /proc/cpufreq ? (its on fc1 - don't remember fc2)
- is /etc/init.d/cpuspeed daemon running? (if not - try starting/restarting)
- once cpuspeed starts - do the following commands change the state?
   killall -SIGUSR1 cpuspeed  # force max freq
   killall -SIGUSR2 cpuspeed  # force min freq
   killall -SIGHUP cpuspeed   # go back to dynamic freq scaling

Satish




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