[ltp] cpufreq speeds below 600 MHz?

[Ramon Casellas]

On Tue, 14 Oct 2003, Andrew Moore wrote:

>
> Anyway, CPU speed adjustments are now working, and they bottom out
> at 600 MHz.  In the interest of getting the T40's fans to turn off
> completely, is there any way to get the CPU to run even lower?


Hi,

The Good news: It is possible (I don't know with a T40, I'm using a X31,
which comes with the same Pentium-M 1.4GHz)

The bad news: there are no bad news, but I have some issues:


I'm currently running 2.6.0-test7, and the thing that puzzles me is
that it depends on whether I turn my laptop on a) on AC power b) on
batteries;

with a)
I have these available frequencies
cat /sys/devices/system/cpu/cpu0/cpufreq/*
174856 349712 524568 699424 874280 1049136 1223992 1398849

with b)
74957 149915 224873 299831 374789 449747 524705 599663
the top is ~600 and the min (!)  75 MHz
IIRC.


the problem is that when booting on batteries + cpudynd or cpufreqd, the
governor is set to "powersave" so my thinkpad boots slooow and practically
unusable (75 MHz). Moreover, if I boot on bat, and I plug the AC
power supply, the max freq remains at 600 MHz. I haven't played much more
than that, but (IMHO) the best thing would be to have all available
freqs at all times, and let the userspace decide....

In summary, I removed the "powersave" option and set it to "performance"
which means that when I run on AC it's about 1400MHz and on batteries it's
about 600 MHz.


 Am I missing something?

Regards,
R.