Ubuntu – How do i make screen dimming work in ubuntu 12.04 (beta 2)

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

Sometimes the graphical login hangs, while you could read an errormessage in the commandline, which indicates to hit the S or the Enter key, which isn't propagated to the graphical login.

So you can watch you HDD-led (Macbooks have such a thing too, do they?) to settle, which indicates, no loading and logging is going on and just hit those keys for good luck, keeping an eye on the LED to check if it has influence.

Or hit Ctrl+Alt+F1 (or F2, F3, ... F4) to get to the pure text screens. F1 should show the logging messages, with error cause as the last message(s). Alt+F7 (maybe F5) will bring you back into the graphical mode.

Or edit grub while booting, hitting e will give you an edit line, there you can remove 'quiet' and 'splash' from the kernel options. This will keep you longer in touch with the messages, and maybe you can read more about the cause.

Next option: Boot from a live cd, mount your system, and read the logfiles in /var/log, most recent files first, boot.log, kernel.log, syslog.

Afaik, Grub has a minimal HDD-access build in, so maybe you can even inspect logfiles from the grub bootscreen, but I don't know from my heart what key to hit, to do so. But there should be a help message, which get's you started.