<mail link="fragfred@gmx.de">Dennis Nienh&#252;ser</mail>

  <mail link="fragfred@gmx.de">Dennis Nienhüser</mail>

<version>1.17</version>

<version>1.18</version>

<date>October 10, 2004</date>

<date>December 01, 2004</date>

Decide yourself whether you want to enable Software Suspend, Suspend-to-Disk

Decide yourself whether you want to enable Software Suspend, Suspend-to-Disk and

and Sleep States (see below). If you own an ASUS, Medion or Toshiba laptop,

Sleep States (see below). If you own an ASUS, Medion or Toshiba laptop, enable

enable the appropriate section.

the appropriate section. Recent kernel versions (2.6.9 and later) include an

<e>'ondemand' governor</e> for CPU Frequency Scaling, activate it as well when

using such a kernel.

</p>

<p>

The kernel has to know how to enable CPU frequency scaling on your processor. As

each type of CPU has a different interface, you've got to choose the right

driver for your processor. Be careful here - enabling <e>Intel Pentium 4 clock

modulation</e> on a Pentium M system will lead to strange results for example.

Consult the kernel documentation if you're unsure which one to take.

the sleep button. Every acpi event recognized by the kernel is catched by acpid

the sleep button. Create the following files to switch between <e>default</e>

which calls <path>/etc/acpi/default.sh</path>. Here is a basic modification

and <e>battery</e> runlevel depending on the power source:

supporting runlevel switching:

</p>

</p>

<pre caption="/etc/acpi/switch_runlevel.conf">

<pre caption="Event driven runlevel switching with acpid">

#!/bin/bash

#!/bin/sh

# This runlevel will be used in AC mode

set $*

#RUNLEVEL_AC="default"

group=${1/\/*/}

# This runlevel will be used in battery mode

action=${1/*\//}

#RUNLEVEL_BATTERY="battery"

<comment># runlevel to use in AC mode</comment>

# This file indicates the AC state

RLVL_AC="default"

# It's location may vary on your system. The script checks for

<comment># runlevel to use in battery mode</comment>

# /proc/acpi/ac_adapter/AC/state, /proc/acpi/ac_adapter/AC0/state,

RLVL_BATTERY="battery"

# /proc/acpi/ac_adapter/AC1/state and /proc/acpi/ac_adapter/AC2/state

# If it is something else on your system, uncomment the next line

<comment># file indicating the AC state. Verify the filename before using</comment>

# and change appropriately.

AC_STATE="/proc/acpi/ac_adapter/AC/state"

#AC_STATE="/proc/acpi/ac_adapter/AC/state"

<comment># this string means running on AC</comment>

</pre>

AC_ON="on-line"

<comment># this string means running on batteries</comment>

<pre caption="/etc/acpi/switch_runlevel.sh">

AC_OFF="off-line"

#!/bin/bash

RUNLEVEL_AC="default"

RUNLEVEL_BATTERY="battery"

if [ -f '/proc/acpi/ac_adapter/AC0/state' ]

then

    AC_STATE="/proc/acpi/ac_adapter/AC0/state"

elif [ -f '/proc/acpi/ac_adapter/AC1/state' ]

then

    AC_STATE="/proc/acpi/ac_adapter/AC1/state"

elif [ -f '/proc/acpi/ac_adapter/AC2/state' ]

then

    AC_STATE="/proc/acpi/ac_adapter/AC2/state"

else

    AC_STATE="/proc/acpi/ac_adapter/AC/state"

fi

source /etc/acpi/switch_runlevel.conf

  if [[ "$(grep ${AC_OFF} ${AC_STATE})" != "" && "$(cat /var/lib/init.d/softlevel)" != "${RLVL_BATTERY}" ]]

    if [ ! -d "/etc/runlevels/${RUNLEVEL_AC}" ]

    logger "Switching to ${RLVL_BATTERY} runlevel"

        logger "${0}: Runlevel ${RUNLEVEL_AC} does not exist. Aborting."

    /sbin/rc ${RLVL_BATTERY}

        exit 1

  elif [[ "$(grep ${AC_ON} ${AC_STATE})" != "" && "$(cat /var/lib/init.d/softlevel)" != "${RLVL_AC}" ]]

    fi

    if [ ! -d "/etc/runlevels/${RUNLEVEL_BATTERY}" ]

    logger "Switching to ${RLVL_AC} runlevel"

        logger "${0}: Runlevel ${RUNLEVEL_BATTERY} does not exist. Aborting."

    /sbin/rc ${RLVL_AC}

        exit 1

    fi

    if [ ! -f "${AC_STATE}" ]

    then

        logger "${0}: File ${AC_STATE} does not exist. Aborting"

        exit 1

    fi

    if [[ "$(grep off-line ${AC_STATE})" != "" && "$(cat /var/lib/init.d/softlevel)" != "${RUNLEVEL_BATTERY}" ]]

    then

        logger "Switching to ${RUNLEVEL_BATTERY} runlevel"

        /sbin/rc ${RUNLEVEL_BATTERY}

    elif [[ "$(grep on-line ${AC_STATE})" != "" && "$(cat /var/lib/init.d/softlevel)" != "${RUNLEVEL_AC}" ]]

    then

        logger "Switching to ${RUNLEVEL_AC} runlevel"

        /sbin/rc ${RUNLEVEL_AC}

case "$group" in

<pre caption="/etc/acpi/events/pmg_battery">

  battery)

event=battery.*

    case "$action" in

action=/etc/acpi/actions/pmg_battery.sh %e

      battery) 

</pre>

        SwitchRunlevel

        ;;

<pre caption="/etc/acpi/actions/pmg_ac_adapter.sh">

      *) 

#! /bin/bash

        logger "ACPI group battery / action $action is not defined"

        ;;

source /etc/acpi/switch_runlevel.sh

    esac

SwitchRunlevel

    ;;

</pre>

  ac_adapter)

<pre caption="/etc/acpi/actions/pmg_battery.sh">

    case "$action" in

#! /bin/bash

      ac_adapter)

        SwitchRunlevel

source /etc/acpi/switch_runlevel.sh

        ;;

SwitchRunlevel

      *)

        logger "ACPI group ac_adapter / action $action is not defined"

        ;;

    esac

    ;;

  *)

    logger "ACPI group $group / action $action is not defined"

    ;;

esac

/etc/acpi/default.sh "battery/battery"

/etc/acpi/actions/pmg_battery.sh "battery/battery"

set the appropriate frequency automatically. A couple of user space programs

set the appropriate frequency automatically. There are many different approaches

like to do it for you. The following table gives a quick overview to help you

to do this. The following table gives a quick overview to help you decide on one

decide on one of them.

of them. It's roughly seperated in three categories <e>kernel</e> for approaches

that only need kernel support, <e>daemon</e> for programs that run in the

background and <e>graphical</e> for programs that provide a GUI for easy

configuration and changes.

  <th>Pro</th>

  <th>Category</th>

  <th>Con</th>

  <th>Switch decision</th>

  <th>Kernel governors</th>

  <th>Further governors</th>

  <th>Comments</th>

</tr>

<tr>

  <ti>'ondemand' governor</ti>

  <ti>Kernel</ti>

  <ti>CPU load</ti>

  <ti>N.A.</ti>

  <ti>N.A.</ti>

  <ti>

    Further tuning through files in

    <path>/sys/devices/system/cpu/cpu0/cpufreq/ondemand/</path>. Still requires

    userland tools (programs, scripts) if governor switching or similar is

    desired.

  </ti>

  <ti>Also supports disk standby</ti>

  <ti>Daemon</ti>

  <ti></ti>

  <ti>CPU load</ti>

  <ti>None</ti>

  <ti>Dynamic</ti>

  <ti>

    Also supports disk standby - notice however that <e>laptop mode</e> in most

    cases will do a better job.

  </ti>

  <ti><uri link="http://sourceforge.net/projects/cpufreqd/">cpufreq</uri></ti>

  <ti><uri link="http://sourceforge.net/projects/cpufreqd/">cpufreqd</uri></ti>

  <ti>Sophisticated setup possible</ti>

  <ti>Daemon</ti>

  <ti>Complicated setup</ti>

  <ti>Battery state, CPU load, running programs</ti>

  <ti>All available</ti>

  <ti>None</ti>

  <ti>

    Sophisticated (but also complicated) setup. An optimal configuration

    requires detailed knowledge of your system.

  </ti>

</tr>

<tr>

  <ti>

    <uri link="http://www.deater.net/john/powernowd.html">powernowd</uri>

  </ti>

  <ti>Daemon</ti>

  <ti>CPU load</ti>

  <ti>None</ti>

  <ti>Passive, sine, aggressive</ti>

  <ti>

    Supports SMP.

  </ti>

    Small yet powerful<br />

    Gnome application, a graphical tool to set CPU frequency manually. It does

    Useful client/server interface

    not offer any automation and is mainly listed for the sake of completeness.

  <ti><uri link="http://www.deater.net/john/powernowd.html">powernowd</uri></ti>

  <ti>klaptopdaemon</ti>

  <ti>Supports SMP</ti>

  <ti>Graphical</ti>

  <ti></ti>

  <ti>Battery state</ti>

  <ti>All available</ti>

  <ti>None</ti>

  <ti>

    KDE only, 'ondemand' governor required for dynamic frequency scaling.

  </ti>

do so is monitoring the CPU speed while working with your laptop:

do so is monitoring CPU speed while working with your laptop:

To start and stop laptop-mode, create a script /etc/init.d/laptop-mode. You can

Besides kernel support you also need a script that controls starting and

take the one included in

stopping of laptop-mode. The package <c>laptop-mode-tools</c> contains it.

<path>/usr/src/linux/Documentation/laptop-mode.txt</path>. Onces it's ready,

make sure it gets called.

# <i>rc-update add laptop-mode battery</i>

# <i>emerge laptop-mode-tools</i>

<warn>

<p>

Once again: Be careful with sleep/spin down settings of your hard drive.

<c>laptop-mode-tools</c> has it's configuration file in

Setting it to small values might wear out your drive and lose warranty. Be sure

<path>/etc/laptop-mode/laptop-mode.conf</path>. Adjust it the way you like it,

to read the documentation in laptop-mode.txt. Make sure to stop laptop-mode

it's well commented. If you have <e>apm</e> or <e>acpi</e> in your USE flags,

before your battery runs out of power and data gets written to disk - otherwise

laptop-mode will be started automatically in battery mode. Otherwise you can

you will at least lose the last 10 minutes of your work.

automate it by running <c>rc-update add laptop-mode battery</c>.

</warn>

</p>