Fiat Lux
Workaround
xbacklight =50
Hypothesis
Hardware?
Driver?
Multiple device?
Linux
+
Recent hardware
Analysis
What happens when I press those buttons?
/sys/class/backlight/acpi_video0/brightness
Hacking it
inotify
while inofifywait -e modify -s $file; do
xbacklight "=$(cat $file)"
done+ Works
- Manual
Automagic
CLI tool
Daemon
backlight_watcher () {
while inofifywait -e modify -s $file; do
xbacklight "=$(cat $file)"
done
}
nohup backlight_watcher &Service
backlight_watcher_start () {
nohup backlight_watcher &
}
backlight_watcher_stop () {
pkill -f inotifywait
}
backlight_watcher_status () {
pgrep -fl inotifywait
}Start at login
- init
- upstart
- systemd
SystemD
No display!
Solutions
- User space
- Manual display
[Unit]
Description=Backlight
[Service]
Type=forking
ExecStart=backlight-watcher start
ExecStop=backlight-watcher stop
[Install]
Are we there yet?
[Unit]
Description=Backlight
[Service]
Type=forking
Environment=DISPLAY=:0 XAUTHORITY=/run/user/1000/gdm/Xauthority
ExecStart=backlight-watcher start
ExecStop=backlight-watcher stop
[Install]Does not work...
3 days later...
[Unit]
Description=Backlight
[Service]
Type=forking
Environment=DISPLAY=:1 XAUTHORITY=/run/user/1000/gdm/Xauthority
ExecStart=backlight-watcher start
ExecStop=backlight-watcher stop
[Install]