cpufreq changes unwanted

[Hans <hans.ullrich@loop.de>]

Hello list,

I discovered, that the cpu frequency is been set automatically to "high", 
although I forced it to stay low.

To do this, I wrote a script:
---

#!/bin/sh

cpufreq-set -c 0 -u 1000MHz
cpufreq-set -c 1 -u 1000MHz
---

This script, executed with root permissions, is setting the cpu frequency to 
low.

See:
LANG=C 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: 1000 MHz - 1.67 GHz
  available frequency steps: 1.67 GHz, 1.33 GHz, 1000 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, 
performance, schedutil
  current policy: frequency should be within 1000 MHz and 1000 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1000 MHz (asserted by call to hardware).
  cpufreq stats: 1.67 GHz:25.16%, 1.33 GHz:15.97%, 1000 MHz:58.87%  (162680)
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 10.0 us.
  hardware limits: 1000 MHz - 1.67 GHz
  available frequency steps: 1.67 GHz, 1.33 GHz, 1000 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, 
performance, schedutil
  current policy: frequency should be within 1000 MHz and 1000 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1000 MHz (asserted by call to hardware).
  cpufreq stats: 1.67 GHz:23.49%, 1.33 GHz:16.34%, 1000 MHz:60.17%  (170410)

------

But after some time, suddenly the frequency is up to 1,67 GHz again. IMHO only 
an application like kmail or anything else might change this.

Is there something known about?  Is this a bug?

Best regards

Hans