Code/tp-fancontrol-basic

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  1. !/bin/bash
  1. This script dynamically controls fan speed on some ThinkPad models
  2. according to user-defined temperature thresholds. It implements its
  3. own decision algorithm, overriding the ThinkPad embedded
  4. controller. It also implements a workaround for the fan noise pulse
  5. experienced every few seconds on some ThinkPads.
  6. The script requires the ibm_acpi patch at
  7. http://thinkwiki.org/wiki/Patch_for_controlling_fan_speed
  8. WARNING: This script relies on undocumented hardware features and
  9. overrides nominal hardware behavior. It may thus cause arbitrary
  10. damage to your laptop or data. Watch your temperatures!
  11. 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 FAN=$IBM_ACPI/fan INTERVAL=3 VERBOSE=true DRY_RUN=false

"$1" == "-t" && { DRY_RUN=true; echo "$0: Dry run, will not change fan state."; }

  1. Enable the fan in default mode if anything goes wrong:

set -e -E -u $DRY_RUN || trap "echo enable > $FAN; exit 0" EXIT HUP INT ABRT QUIT SEGV TERM


thermometer() { # output list of temperatures

   read X Y < $IBM_ACPI/thermal
    "$X" == "temperatures:"  || { 

echo "$0: Bad temperatures: $X $Y" >&2 exit 1

   }
   echo "$Y"; 

}

speedometer() { # output fan speed

   cat $FAN | sed '/^speed/!d; s/speed:[ \t]*//'

}

IDX=0 MAX_IDX=$(( ${#LEVELS[@]} - 1 )) SETTLE=0

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
   OLDLEVEL=${LEVELS[$IDX]}
   NEWLEVEL=${LEVELS[$NEWIDX]}
   $VERBOSE && echo "tpfan: Temps: $TEMPS   Fan: $SPEED   Level: $OLDLEVEL->$NEWLEVEL"
   $DRY_RUN || echo level $NEWLEVEL > $FAN
   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 $DRY_RUN || echo level disengaged >> $FAN sleep 0.5 fi else SETTLE=6 fi

   fi
   IDX=$NEWIDX

done