Brightness is reset to maximum after waking up from suspend or lock screen

This question is somewhat related to this question: Brightness is reset to Maximum on every Restart

Basically, I modified /etc/rc.local to set the brightness, as detailed in this answer, so on startup the brightness does get set to the correct value. However, when I suspend my laptop and wake it up, or simply close the screen and reopen it, the brightness gets reset to the maximum.

My machine runs Ubuntu 14.04 + Gnome 3. The machine is a Thinkpad X1 Carbon.

What's the solution?

1 Answer

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.