How to configure acpid

Introduction

Basically, acpid just executes scripts residing in /etc/acpi/actions. Which script to launch at which event is configured in several files in /etc/acpi/events. All actions are documented in /var/log/acpid in older versions of acpid and to /var/log/messages, and /var/log/syslog via the syslog interface in newer versions >~1.0.6.

Sources of Information

• $ man acpid holds detailed information on how to configure acpid.
• The ibm-acpi package includes example scripts in the config folder inside the tarball. They are a good starting point to adjust them to your needs.
• You also might want to have a look at the ACPI section of the Configs page or the Scripts repository.
• And you can find information about the event strings ibm-acpi generates for certain keys at the Special Keys HOWTO.

Example: go to sleep on lid close

To make the ThinkPad go to sleep when you close the lid, you need to add an event handler for the lid event and an action script that takes care of going to sleep and resuming.

Event Script

The event script needs to be created within /etc/acpi/events and can have any name you like. In this case we call it lid because it will trigger the lid event. Do # vi /etc/acpi/events/lid and make it look like this:

event=button/lid
action=/etc/acpi/actions/sleep.sh %e

The "event" line is a regular expression specifying the events we're interested in. You can determine what the event strings are from looking at /var/log/acpid after trying to suspend, close the lid, etc. . You can find information about the event strings ibm-acpi generates for certain keys at the Special Keys HOWTO.

The "action" line is the command to be executed when these events are dispatched. In this example we call the sleep.sh script residing in /etc/acpi/actions and pass the event description text using the %e placeholder.

For the script you can use the hibernate script of Tux On Ice (it is independent of the suspend-to-disk functionality), or any of many examples available on the web, such as the one below.

NOTE!

To make your changes take effect after adding or modifying the events files you must do a kill -SIGHUP `pidof acpid`

Action Script

Our example /etc/acpi/actions/sleep.sh script looks as follows:

#!/bin/sh

# if launched through a lid event and lid is open, do nothing
echo "$1" | grep "button/lid" && grep -q open /proc/acpi/button/lid/LID/state && exit 0

# remove USB 1.1 driver
rmmod uhci_hcd
 
# sync filesystem and clock
sync
/sbin/hwclock --systohc

# switch to console
FGCONSOLE=`fgconsole`
chvt 6
/usr/sbin/radeontool light off

# go to sleep
sleep 5 && echo -n "mem" > /sys/power/state

# readjust the clock (it might be off a bit after suspend)
/sbin/hwclock --adjust
/sbin/hwclock --hctosys

# reload USB 1.1 driver
modprobe uhci_hcd

# turn on the backlight and switch back to X
radeontool light on
chvt $FGCONSOLE

NOTE!

This parts of this script are now part of some distributions, like Debian Etch and you probably don't need to add this script. Look into /etc/acpi/lid.sh, for example.

Explanations

• The lid generates an event for both opening and closing thus requiring that we check its state and only act if it's closed.
• There have been problems encountered with the USB devices not working properly after a resume from suspend. To circumvent those we remove the USB driver prior to suspend and reload it afterwards.
• Note that the # echo -n "mem" > /sys/power/state line does not return until we are revived. So there is only one event generated and there is no need to check the state of anything.
• The console switching code in this script is a special solution for a problem where the backlight doesn't switch off on the T30 and some other models. Before going to sleep, these models switch to console mode which causes the backlight to come back on. So we preemptively switch to console mode and turn off the backlight using radeontool before going to sleep.

Screen blanking script

You might want to be able to switch of the screen using Fn-f3. This is not completely straightforward. You will first need to give permission to the script to muck around with your screen

xhost +local:root 

/etc/acpi/events/sleepbtn contains

event=(button[ /]sleep|ibm/hotkey HKEY 00000080 00001004)
action=/etc/acpi/sleepbtn.sh

And /etc/acpi/sleepbtn.sh is

#!/bin/bash

# simple script to turn the display on or off      #
# By Mahram Z.Foadi                                                           #
# Oct 22 2005                                                                 # 
# thank you linuxquestions.org                                                #
#                                                                             # 
# the following lines must be present in your "/etc/acpi/events/" files. Some #
# systems already have a file called sample.conf in the mentioned directory   #
# rename it to something more meaningful (i.e. acpid.conf) and these lines to #
# the end of it  (you don't HAVE to rename it, you can even create a new file #
# and call it /etc/acpi/events/lid.conf with the 2 lines in it. If you intend #
# to put this file anywhere other than /sbin/lidevent, make sure you make the #
# proper changes in the "action" line below. For example if you are going to  #
# save this script as /usr/bin/mylid.sh then the action line should be:       #
# action=/usr/bin/mylid.sh                                                    #
# be sure both files are executable, writable, and owned by root ONLY because #
# the acpid daemon is most likely running as root in your system              #
#                                                                             #
#     ---- insert the two lines below in /etc/acpi/events/acpid.conf ----     #
# event=button/lid.*                                                          #
# action=/sbin/lidevent                                                       #
#-----------------------------------------------------------------------------#

# default display on current host
DISPLAY=:0.0

# find out if DPMS is enabled
STATUS=`xset -display $DISPLAY -q | grep -e 'DPMS is'`

# enable DPMS if disabled
if [ "$STATUS" == "  DPMS is Disabled" ]
then
	echo "Enabling DPMS ..."
	xset -display $DISPLAY +dpms
fi

 # find out if monitor is on
STATUS=`xset -display $DISPLAY -q | grep 'Monitor'`

if [ "$STATUS" == "  Monitor is On" ]
then
	echo "[`date`] Turning display OFF"
	xset -display $DISPLAY dpms force off
else
	echo "[`date`] Turning display ON"		# shows up in log
	xset -display $DISPLAY dpms force on		# turn monitor on
 	xset -display $DISPLAY s activate		# un-blank monitor
fi

#clean up
unset STATUS

# comment this line out if you're manually running this script from a shell (put a # in front of it)
unset DISPLAY

exit 0

An alternative is to call radeontool (if you have a radeon videocard only of course)

Switch external display

Again make sure that

xhost +local:root  

With the newer versions of X, display switching can be done with xrandr. Create the script /etc/acpi/switchdisplay.sh

#!/bin/csh
/usr/bin/xrandr --output VGA-0 --auto

And /etc/acpi/events/displaybtn

event=ibm/hotkey HKEY 00000080 00001007
action=/etc/acpi/switchdisplay.sh

Troubleshooting

• If something doesn't work, your first action should be a # tail /var/log/acpid. It will tell you a lot about what is going on. If it has "Permission denied" errors, check the permissions of your /etc/acpi/actions scripts (especially make sure that the executable bit is set). Also check the permissions for other involved files like i.e. device nodes.
• For further problems look at the Problems with ACPI suspend-to-ram page.