Ubuntu – Artificially increase maximum screen brightness

I tested a solution that works fine for me. One solution is to add a script file in /etc/pm/power.d/

Just creates a file

sudo vi /etc/pm/power.d/run_after_pwrmanagmt.sh

Then writes this code into this file :

case "${1}" in
    true) #battery_mode
        xinput set-int-prop 12 277 8 2 3 0 0 1 3 2
        echo 4000 > /sys/class/backlight/intel_backlight/brightness
;;
    false) #ac_mode
        xinput set-int-prop 12 277 8 2 3 0 0 1 3 2
        echo 4000 > /sys/class/backlight/intel_backlight/brightness
esac

Now, you need to give execution rights to this file by typing

sudo chmod +x /etc/pm/power.d/run_after_pwrmanagmt.sh

Now it should work fine, just test to plug/unplug your computer. Note that you can do similar things after a suspend (/etc/pm/sleep.d/run_after_sleep.sh), that's how I found out this solution... You will find information on the web...

Note that xinput is just a command for my trackpad to set the middle button working... You should skip the two lines xinput if not needed (or adapt ). For the value 4000, it may be diffrent for each screen, you should first see what is your max value with the command cat /sys/class/backlight/intel_backlight/max_brightness

Hope this helps, and that the moderator will not delete this post since this is an answer and not a question. Thanks

For waking up from suspension, I create the following script /etc/pm/sleep.d/brightness:

#!/bin/sh
case "$1" in
    resume|thaw)
        echo 170 > /sys/class/backlight/intel_backlight/brightness
        ;;
esac

And the permission of the script is -rwxr-xr-x. This should also solve your problem.

But if the screen is dimmed, the brightness is set to maximum after recovering from the dimming.

This is really a bug which should be fixed.

I am using ubuntu 64 bit 14.04 with a Thinkpad T440s.