#! /bin/sh
#
# This script adjusts hard drive APM settings using hdparm. The hardware
# defaults (usually hdparm -B 127) cause excessive head load/unload cycles
# on many modern hard drives. We therefore set hdparm -B 254 while on AC
# power. On battery we set hdparm -B 128; this still does not guarantee
# disk parking, but is safer than causing lots of mechanical wear on disks
# as we seem to get currently with 127.
#
# Refactored from acpi-support's 90-hdparm.sh for pm-utils

if grep -wq "nohdparm" /proc/cmdline ; then
    exit 0
fi

# Do nothing when called via /etc/init.d/acpi-support; udev rules take care
# of setting the initial hdparm policy for us.
if ([ "$previous" ] && [ "$runlevel" ]) || [ "$runlevel" = S ]; then
    exit 0
fi

if [ -e /usr/sbin/laptop_mode ] ; then
	LMT_CONTROL_HD_POWERMGMT=$(. /etc/laptop-mode/laptop-mode.conf && echo "$CONTROL_HD_POWERMGMT")
	if [ "$LMT_CONTROL_HD_POWERMGMT" != 0 ] \
	   && [ -e /var/run/laptop-mode-tools/enabled ]
	then
		# Laptop mode controls hdparm -B settings, we don't.
		exit 0
	fi
fi

. /lib/hdparm/hdparm-functions

resume_hdparm_apm()
{
	for dev in /dev/sd? /dev/hd? ; do
		if [ -b $dev ] && hdparm_try_apm $dev ; then
			# Check for APM support; discard errors since not all
			# drives support HDIO_GET_IDENTITY (-i).
			if hdparm -i $dev 2> /dev/null | grep -q 'AdvancedPM=yes'
			then
				for option in $(hdparm_options $dev); do
					case $option in
						-B*)
							apm_opt=$option
							;;
						*)
							;;
					esac
				done
				if [ -n "$apm_opt" ]; then
					hdparm $apm_opt $dev
				fi
			fi
		fi
	done
}

resume_hdparm_spindown()
{
	for dev in /dev/sd? /dev/hd? ; do
		if [ -b $dev ] && hdparm_try_apm $dev ; then
			# Check for APM support; discard errors since not all
			# drives support HDIO_GET_IDENTITY (-i).
			if hdparm -i $dev 2> /dev/null | grep -q 'AdvancedPM=yes'
			then
				for option in $(hdparm_options $dev); do
					case $option in
						-S*)
							apm_opt=$option
							;;
						*)
							;;
					esac
				done
				if [ -n "$apm_opt" ]; then
					hdparm $apm_opt $dev
				fi
			fi
		fi
	done
}

case "$1" in
	true|false) # powersaving on/off
		resume_hdparm_apm
		;;
	thaw|resume)
		resume_hdparm_apm
		# only set the -S option on resuming, not necessary for power.d
		resume_hdparm_spindown
		;;
	*)
		exit 254
		;;
esac