Force 0 brightness on startup?

General Discussion
1

heyo I’m currently using a laptop with dietpi and its screen is busted. is there a way to force its brightness to 0 or keep it off from startup? currently having to change brightness to 0 in config every time I restart.

2

Interesting that it does not stay at 0 for you after reboot. We just had the topic and the question whether we should add udev rules which set the brightness on every boot, but for us it was persistent, pretty much like when you set brightness via monitor buttons. But probably it simply depends on the screen.

I’ll provide a udev rule to enforce it when I’m back home.

It is about the console only, no desktop/GUI, right?

3

Cool. Yeah I just ssh in Otherwise I run it without ever looking at the screen. Due to the person who owned it before me punching it in the face… I just keep the screen off for saving a small amount of power. Oh also yes console only.

4

Try out this. Check out the path/name of the backlist device:

ls -l /sys/class/backlight/

Then create a file /etc/udev/rules.d/99-brightness.conf with this content:

SUBSYSTEM=="backlight", KERNEL=="deviceName", ACTION=="add", ATTR{brightness}="0"

To put the syntax into words: If a hardware/device event happens, and:

  1. It is a device of the backlight class/subsystem
  2. Its name is deviceName, i.e. its path is /sys/class/backlight/deviceName
  3. The event/action is “add”, i.e. the device has been detected and the kernel adds it to the sysfs
  4. Then set its attribute brightness to the value 0
5

thanks. haven’t messed with it yet. backlight is a minor issue but hopefully this will help me.