Damn Small Linux - Not!

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

After much (failed) effort to get cpufreqd working in DSL, I switched to DSL-N and finally it works. Here's how to get things working in RC4.

Notes
1. cat /proc/cpuinfo model name : Intel(R) Pentium(R) M processor 1.60GHz
2. Although both speedstep-centrino.ko and acpi-cpufreq.ko modules are present in RC4, you can only load one of them and Google seemed to indicate the former was better.
3. apt sources.list edited to Debian stable

1. Enable apt-get in RC4 as per the instructions in the "apt-g" post.
2. Modprobe speedstep-centrino, cpufreq_powersave, cpufreq_userspace & cpufreq_ondemand.
3. apt-get install acpid, cpufreqd & cpufrequtils

Now if I pull the power cable, the cpu frequency will instantly drop from 1.6GHz to 600MHz and you can use the "cpufreq-info" and "cpufreq-set" commands to examine and set the cpufreq powersaving features, for example (using the default cpufreq.conf file):

root@dslbox:~# cpufreq-info
cpufrequtils 0.2: cpufreq-info (C) Dominik Brodowski 2004
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
driver: centrino
CPUs which need to switch frequency at the same time: 0
hardware limits: 600 MHz - 1.60 GHz
available frequency steps: 1.60 GHz, 1.60 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz, 600 MHz
available cpufreq governors: ondemand, userspace, powersave, performance
current policy: frequency should be within 600 MHz and 1.60 GHz.
The governor "powersave" may decide which speed to use
within this range.
current CPU frequency is 600 MHz (asserted by call to hardware).
root@dslbox:~# root@dslbox:~# cpufreq-set -g performance
root@dslbox:~# cpufreq-info
cpufrequtils 0.2: cpufreq-info (C) Dominik Brodowski 2004
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
driver: centrino
CPUs which need to switch frequency at the same time: 0
hardware limits: 600 MHz - 1.60 GHz
available frequency steps: 1.60 GHz, 1.60 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz, 600 MHz
available cpufreq governors: ondemand, userspace, powersave, performance
current policy: frequency should be within 600 MHz and 1.60 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 1.60 GHz (asserted by call to hardware).

Juanito · Joined: 11 Sep 2006 Posts: 88 Location: Dubai, U.A.E.

For those that are interested to try it, cpufreq_combo.dsl is posted in the testing area of the DSL-N repository. This dsl will load the acpid and cpufreqd daemons and the cpufreq utils package.

On my laptop (Dell Latitude D400), loading this dsl makes a big difference to the battery life - more than one hour additional use.

Note that you have to load the module relevent to your processor for this to work. The choices are listed below - note I didn't check if all of these are compiled into RC4:

AMD Mobile K6-2/K6-3 PowerNow! (module POWERNOW_K6)
AMD Mobile Athlon/Duron K7 PowerNow! (module POWERNOW_K7)
AMD Opteron/Athlon64 PowerNow! (module POWERNOW_K8)
VIA Cyrix III Longhaul (module LONGHAUL)
Intel Speedstep (PIIX4) (module SPEEDSTEP_PIIX4)
Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface) (module SPEEDSTEP_SMI)
Intel Speedstep (ICH) (module SPEEDSTEP_ICH)
Intel Pentium-M Enhanced SpeedStep (module SPEEDSTEP_CENTRINO)
Intel Pentium 4 clock modulation (module P4_CLOCKMOD)
Transmeta LongRun (module LONGRUN)

Once you have chosen the module relevant to your processor, then you need to enter the following commands to get going:

sudo modprobe speedstep-centrino (in the case of my Dell D400)
sudo modprobe cpufreq_powersave
sudo modprobe cpufreq_userspace
sudo modprobe cpufreq_ondemand
mydsl-load /path/cpufreq_combo.dsl