#!/bin/sh
# Script to fix the hard disk power management bug.
# by Hansgeorg Schwibbe (hansgeorg.schwibbe@gmx.de)

device=$1;
deviceName="${device##*/}";
installRootPath="/etc/acpi/";
scriptName="hdparm-apm-"$deviceName".sh";
scriptPath=$installRootPath$scriptName;
linkName="99-"$scriptName;
linkPath1=$installRootPath"start.d/"$linkName;
linkPath2=$installRootPath"resume.d/"$linkName;
linkPath3=$installRootPath"ac.d/"$linkName;
linkPath4=$installRootPath"battery.d/"$linkName;
scriptCode="#!/bin/sh\n\n
if on_ac_power; then\n
\t# on AC so don't do any head parking\n
\thdparm -B 254 $device\n
else\n
\t# either on battery or power status could not be determined\n
\t# so quickly park the head to protect the disk\n
\thdparm -B 253 $device\n
fi\n";

case "$2" in
  install)
    echo "Installing power management fix for $device";

    # test the block device
    if ! [ -b $device ]; then
      echo "$device is not a valid block device!";  
      exit 1;
    fi

    # construct the script
    echo $scriptCode > $scriptPath;
    chmod 0755 $scriptPath;

    # link the script
    ln -s $scriptPath $linkPath1;
    ln -s $scriptPath $linkPath2;
    ln -s $scriptPath $linkPath3;
    ln -s $scriptPath $linkPath4;
    exit 0;
  ;;

  remove)
    echo "Removing power management fix for $device";

    # remove all installation files
    rm $scriptPath;
    rm $linkPath1;
    rm $linkPath2;
    rm $linkPath3;
    rm $linkPath4;
    exit 0;
  ;;

  *)
    echo "Usage: $0 device {install|remove}";
    exit 1;
  ;;
esac