etc . acpi . events . power-loss

event=ac_adapter
action=/root/power-loss.sh "%e"

root . power-loss.sh

#!/bin/bash

TIMEOUT=5

echo "$(date +%s) Catch event: $@" >> /var/log/power-loss.log

function set_scsi_host_power () {
	for host in $(find /sys/class/scsi_host/ -maxdepth 1 -name 'host[0-9]'); do
		f="$host/link_power_management_policy"
		[[ -f $f ]] && echo "$1" > "$f"
	done
}

function set_cpu_governor () {
	for cpu in $(find /sys/devices/system/cpu/ -maxdepth 1 -name 'cpu[0-9]'); do
		f="$cpu/cpufreq/scaling_governor"
		[[ -f $f ]] && echo "$1" > "$f"
	done
}

function set_sched_mc_power_savings () {
	if [[ -f /sys/devices/system/cpu/sched_mc_power_savings ]]; then
		echo "$1" > /sys/devices/system/cpu/sched_mc_power_savings
	fi
}

function set_snd_hda_intel_power_save () {
	if [[ -f /sys/module/snd_hda_intel/parameters/power_save ]]; then
		echo "$1" > /sys/module/snd_hda_intel/parameters/power_save
	fi
}

function set_pcie_aspm_policy () {
	if [[ -f /sys/module/pcie_aspm/parameters/policy ]]; then
		echo "$1" > /sys/module/pcie_aspm/parameters/policy
	fi
}

function set_acpi_video0_brightness () {
	if [[ -f /sys/class/backlight/acpi_video0/brightness ]]; then
		if [[ $1 == max ]] && [[ -f /sys/class/backlight/acpi_video0/max_brightness ]]; then
			brightness="$(cat /sys/class/backlight/acpi_video0/max_brightness)"
		else
			brightness="$1"
		fi
		echo "$brightness" > /sys/class/backlight/acpi_video0/brightness
	fi
}

if on_ac_power; then
	echo "$(date +%s) AC power is ON." >> /var/log/power-loss.log
	echo 0 > /proc/sys/vm/laptop_mode
	set_scsi_host_power max_performance
	set_cpu_governor conservative
	set_sched_mc_power_savings 0
	set_snd_hda_intel_power_save 0
	modprobe uvcvideo
	set_pcie_aspm_policy performance
	set_acpi_video0_brightness max
		# Disabled due to waking up alredy sleeping HDD.
	#hdparm -B 127 -S 240 /dev/sdb
else
	echo "$(date +%s) AC power is OFF." >> /var/log/power-loss.log
	echo 5 > /proc/sys/vm/laptop_mode
	set_scsi_host_power min_power
	set_cpu_governor powersave
	set_sched_mc_power_savings 1
	set_snd_hda_intel_power_save 10
	modprobe -r uvcvideo
	set_pcie_aspm_policy powersave
	set_acpi_video0_brightness 0
		# Disabled due to waking up alredy sleeping HDD.
	#hdparm -B 1 -S 1 /dev/sdb
	
	sleep $TIMEOUT
	# if still no power -> suspend
	if ! on_ac_power; then
		echo "$(date +%s) No AC power in $TIMEOUT sec! Suspending..." >> /var/log/power-loss.log
		loginctl lock-sessions >> /var/log/power-loss.log &
		pm-suspend >> /var/log/power-loss.log & 
	else
		echo "$(date +%s) AC power back in $TIMEOUT sec! Not suspending." >> /var/log/power-loss.log
	fi
fi