intel-hda-powersave

#! /bin/sh
#
# Laptop mode tools module: Intel HDA integrated audio power saving mode.
#

if [ x$CONTROL_INTEL_HDA_POWER = x1 ]  || [ x$ENABLE_AUTO_MODULES = x1 -a x$CONTROL_INTEL_HDA_POWER = xauto ]; then
	if [ $ON_AC -eq 1 ]; then
		if [ "$ACTIVATE" -eq 1 ]; then
			INTEL_HDA_POWERSAVE="$LM_AC_INTEL_HDA_POWERSAVE"
		else
			INTEL_HDA_POWERSAVE="$NOLM_AC_INTEL_HDA_POWERSAVE"
		fi
	else
		INTEL_HDA_POWERSAVE="$BATT_INTEL_HDA_POWERSAVE"
	fi

	# Handle Intel HDA Power Save
	if [ -w /sys/module/snd_hda_intel/parameters/power_save ]; then
		if [ x$INTEL_HDA_POWERSAVE = x1 ]; then
			echo $INTEL_HDA_DEVICE_TIMEOUT > /sys/module/snd_hda_intel/parameters/power_save
			log "VERBOSE" "Intel HDA power save mode enabled with timeout $INTEL_HDA_DEVICE_TIMEOUT."
			if [ -c /dev/dsp ]; then
				# This can fail if the audio device is busy.
				# Since this failure is non-fatal (worst case is that the timer changes
				# don't get activated), we don't bother if it was successful or not
				#(exec 2>/dev/null; echo 1 > /dev/dsp;)
				# Better way
				echo 1 2>/dev/null >/dev/dsp
				log "VERBOSE" "Initialize timer change by close/open /dev/dsp"
			fi
		else
			echo 0 > /sys/module/snd_hda_intel/parameters/power_save
			log "VERBOSE" "Intel HDA power save mode disabled."
		fi
	else
		log "VERBOSE" "Intel HDA power saving is not available on this system."
	fi

	# Handle Intel HDA Controller Power Savings.
	if [ x$INTEL_HDA_DEVICE_CONTROLLER = x1 -a x$INTEL_HDA_POWERSAVE = x1 ]; then
		POWER_SAVE="Y"
	else
		POWER_SAVE="N"
	fi

	if [ -w /sys/module/snd_hda_intel/parameters/power_save_controller ]; then
		echo $POWER_SAVE > /sys/module/snd_hda_intel/parameters/power_save_controller
		log "VERBOSE" "Intel HDA Controller power save set to $POWER_SAVE."
	else
		log "VERBOSE" "Sound Card doesn't seem to support Controller Power Save."
	fi
else
	log "VERBOSE" "Intel HDA audio power setting is disabled."
fi