Talk:Fan control scripts

Wyrfel, are you sure the recent (19:54, 27 Oct 2005) cosmetic change was a good idea? The extensive chunks of code make it hard to grok the structure of the article in the absense of separator lines (which "===" doesn't have). --Thinker 22:10, 27 Oct 2005 (CEST)

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We can discuss this. From my point of view, the chunks of code distinguish themselves from each other quite well, because they are each in one code block.

I do not like the = section level - and so far we avoided them on all pages - because

• it generates H1 headings, which is the same as the page heading,
• having more than one level with the hbars is confusing/less readable, because they are not very well distinguishable. This way i.e. the "Other" section looked like a separate empty secion.

I think the way it's now, the separator lines make it possible to easily distinguish the different main sections, while when you have both levels with separator lines, an additional task of distinguishing H1 and H2 separators is necessary.

However, i see your point as well and would like to hear more opinions/arguments.

Wyrfel 22:31, 27 Oct 2005 (CEST)

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bash script with fine control over fan speed (for unpatched kernels)

Here's an alternative variable speed control script that doesn't need the patch for controlling fan speed. It requires only ibm-acpi 0.11 or higher (e.g., as found in kernel 2.6.14 and higher) with the experimental=1 module parameter.

Alas, at the moment I don't have a suitable to test it on. Can someone give it a try and report?

(fixed and moved to article)

--Thinker 15:07, 3 Nov 2005 (CET)

IBM_ACPI was defined twice by accident I guess (changed above), but otherwise it seems to work fine, went from level 0 (cold machine) to 7 while compiling the kernel and now back to level 2 now at about 53 degrees Celsius.

--spiney 10:31, 5 Nov 2005 (CET)

Oops, yes. The IBM_ACPI=/tmp was just for testing (in the temporary absense of a ThinkPad, I wrote stuff to /tmp/thermal manually to test the script...). Fixed and moved to the article. Thanks!

--Thinker 12:58, 5 Nov 2005 (CET)

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updated bash script for unpatched kernels

Feedback welcome.

(see below)

BTW, Thinker, I couldn't get the backgrounding of a function to work, and at the moment I'm not quiet sure that's even possible without it exiting once the main script exits.

If you think it's fine otherwise (after all your the author of the original script) we might put it into the article.

--spiney 19:01, 8 Nov 2005 (CET)

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How about this? Used non-exec backgrounding, option to kill daemon, handling of initial (unknown) state and a few cleanups.

#!/bin/bash

# This script dynamically controls fan speed on some ThinkPad models
# according to user-defined temperature thresholds.  It implements its
# own decision algorithm, overriding the ThinkPad embedded
# controller. It also implements a workaround for the fan noise pulse
# experienced every few seconds on some ThinkPads.
#
# WARNING: This script relies on undocumented hardware features and
# overrides nominal hardware behavior. It may thus cause arbitrary
# damage to your laptop or data. Watch your temperatures!
#
# This file is placed in the public domain and may be freely distributed.

LEVELS=(    0      2      4      7)  # Fan speed levels
UP_TEMPS=(      52     60     68  )  # Speed increase trip points
DOWN_TEMPS=(  48     56     64    )  # Speed decrease trip points

ANTIPULSE=( 0      1      0      0)  # Prevent fan pulsing noise at this level
                                     #   (this also prevents fan speed updates)

IBM_ACPI=/proc/acpi/ibm
PID_FILE=/var/run/tp-fancontrol.pid
INTERVAL=3
VERBOSE=true
DRY_RUN=false
DAEMONIZE=false
AM_DAEMON=false
KILL_DAEMON=false
SYSLOG=false
LOGGER=/usr/bin/logger 

usage() {
    echo "Usage: $0 [OPTION]..."
    echo
    echo "Available options:"
    echo "   -t     test mode"
    echo "   -q     quiet mode"
    echo "   -d     daemon mode, go into background (implies -q)"
    echo "   -l     log to syslog"
    echo "   -p     pid file location for daemon mode, default: $PID_FILE"
    echo "   -k     kill daemon (ignores all but -p)"
    exit 1
}

while getopts 'qtdlp:kh' OPT; do
    case "$OPT" in
        t) # test mode
            DRY_RUN=true
            ;;
        q) # quiet mode
            VERBOSE=false
            ;;
        d) # go into background and daemonize
            DAEMONIZE=true
            ;;
        l) # log to syslog
            SYSLOG=true
            ;;
        p) # different pidfile
            PID_FILE="$OPTARG"
            ;;
        k) # kill daemon
            KILL_DAEMON=true
            ;;
        h) # short help
            usage
            ;;
        \?) # error
            usage
            ;;
    esac
done
[[ $OPTIND -gt $# ]] || usage  # no non-option args

# no logger found, no syslog capabilities
$SYSLOG && [[ ! -x $LOGGER ]] && SYSLOG=false

if $DRY_RUN; then
    echo "$0: Dry run, will not change fan state."
    VERBOSE=true
    DAEMONIZE=false
fi

thermometer() { # output list of temperatures
    read X Y < $IBM_ACPI/thermal
    if ! [[ "$X" == "temperatures:" ]]; then
        echo "$0: Bad temperatures: $X $Y" >&2
        exit 1
    fi
    echo "$Y";
}

speedometer() { # output fan speed RPM
    sed -n 's/^speed:[ \t]*//p' $IBM_ACPI/fan
}

setlevel() { # set fan speed level
    $DRY_RUN || echo 0x2F $1 > $IBM_ACPI/ecdump
}

cleanup() { # clean up after work
    $AM_DAEMON && rm -f $PID_FILE 2> /dev/null
    $SYSLOG && $LOGGER -t "`basename $0`[$$]" \
               "Shutting down, switching to automatic fan control"
    $DRY_RUN || echo enable > $IBM_ACPI/fan
}

control_fan() {
    # Enable the fan in default mode if anything goes wrong:
    set -e -E -u
    trap "cleanup; exit 2" HUP INT ABRT QUIT SEGV TERM
    trap "cleanup" EXIT

    IDX=0
    MAX_IDX=$(( ${#LEVELS[@]} - 1 ))
    SETTLE=0
    FIRST=true
    $SYSLOG && $LOGGER -t "`basename $0`[$$]" "Starting dynamic fan control"

    # Control loop:
    while true; do
        TEMPS=`thermometer`
        $VERBOSE && SPEED=`speedometer`
    
        # Calculate new level
        NEWIDX=$IDX
        DOWN=$(( IDX > 0 ))
        for TEMP in $TEMPS; do
            # Increase speed as much as needed
            while [[ $NEWIDX -lt $MAX_IDX ]] && 
                  [[ $TEMP -ge ${UP_TEMPS[$NEWIDX]} ]]; do
                (( NEWIDX ++ ))
                DOWN=0
            done
            # Allow decrease (by one index)?
            if [[ $DOWN == 1 ]] &&
               [[ $TEMP -gt ${DOWN_TEMPS[$(( IDX - 1 ))]} ]]; then
                DOWN=0
            fi
        done
        if [[ $DOWN == 1 ]]; then
            NEWIDX=$(( IDX - 1 ))
        fi
    
        # Transition
        $FIRST && OLDLEVEL=unknown || OLDLEVEL=${LEVELS[$IDX]}
        NEWLEVEL=${LEVELS[$NEWIDX]}
        $VERBOSE && echo "Temps: $TEMPS   Fan: $SPEED   Level: $OLDLEVEL->$NEWLEVEL"
        $SYSLOG && [[ $OLDLEVEL != $NEWLEVEL ]] && 
                $LOGGER -t "`basename $0`[$$]" "Changing fan level: $OLDLEVEL->$NEWLEVEL"

        setlevel $NEWLEVEL
    
        sleep $INTERVAL
    
        # If needed, apply anti-pulsing hack after a settle-down period:
        if [[ ${ANTIPULSE[${NEWIDX}]} == 1 ]]; then
            if [[ $NEWLEVEL == $OLDLEVEL ]]; then
                if [[ $SETTLE -ge 0 ]]; then
                    (( SETTLE -= INTERVAL ))
                else
                    setlevel 0x40 # disengaged
                    sleep 0.5
                fi
            else
                SETTLE=6
            fi
        fi
    
        IDX=$NEWIDX
	FIRST=false
    done
}

if $KILL_DAEMON ; then 
    if [ -f $PID_FILE ]; then
	set -e
	DPID="`cat $PID_FILE`" 
        kill "$DPID"
	rm "$PID_FILE"
	$VERBOSE && echo "Killed process $DPID"
    else
        $VERBOSE && echo "Daemon not running."
        exit 1
    fi
elif $DAEMONIZE ; then
    if [ -e "$PID_FILE" ]; then
        echo "$0: File $PID_FILE already exists, refusing to run."
        exit 1
    else
	AM_DAEMON=true VERBOSE=false control_fan 0<&- 1>&- 2>&- &
        echo $! > "$PID_FILE"
        exit 0
    fi
else
    control_fan
fi

--Thinker 20:28, 8 Nov 2005 (CET)

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Great work, thanks. Just added startup and shutdown messages and made some echos depending on $VERBOSE so you can for instance call script -qk from an init-script without problems. Also set the exit value to non-zero when trying to kill a not running daemon.

Oh, and I incorporated you last minor edit, because that ended up in the version that I put into my last comment. ;)

--spiney 22:18, 8 Nov 2005 (CET)

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