How do I set default brightness after boot?
Your laptop should have /sys/class/backlight. For example, /sys/class/backlight/acpi_video0/brightness. You can write (echo) values to this file to adjust brightness.
cat /sys/class/backlight/acpi_video0/max_brightness > /sys/class/backlight/acpi_video0/brightness
This will set the brightness to max. Just put it in an init script on boot.
my x120e's brightness constantly changing bothers me as well. surprisingly (but not), when i ran
gksudo dmesg > boot.messages
and opened boot.messages in a text editor, i noticed this message:
[Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
multiple times, as well as some interesting others. paste that into Google and you'll find Cannibal's Candy [wordpress] - who provides an in-depth look at ACPI and a method for universally setting the screen brightness (+ so much more):
DSDT editing: Put an end to your ACPI woes
yep, prepare your mind to be blown. i'm working through CC's post right now, but thought i would share. best of luck!
running Linux Mint Debian (amd64) on a Thinkpad x120e