I have dual-booted my Macbook Pro with Ubuntu 12.04 . Whenever i log-in to Ubuntu, it does so with full screen brightness and keyboard backlight at full . How do i get rid of this? How can i tweak the start-up setting for screen brightness and disable keyboard backlight at start-up?


To fix the screen brightness on my Macbook I stopped the apple_bl kernel module from being loaded. This seem to fix this for me.

  1. Create a file called: /etc/modprobe.d/blacklist-applebl.conf
  2. In the above file add the line:

     blacklist apple_bl
  3. Reboot.

  • I tried this, but it still reboots with maximum brightness. – hektor May 26 '12 at 15:34
  • OK i read the question wrong. My install also always starts at full brightnesss. But I usually use suspend. Can you control the brightness using the keys? – Tim May 29 '12 at 2:43
  • Yep i can use the keys to control the brightness. – hektor May 29 '12 at 13:02

On my 11.2 MacBook Pro running Ubuntu 13.10, I got satisfactory results with this command, which makes an upstart task to dim them upon starting the login screen:

sudo cat > /etc/init/mbp-save-battery.conf << EOF
description "Lower screen and keyboard backlight brightness on boot"


start on login-session-start

  # lower screen brightness
  echo "35" > /sys/class/backlight/acpi_video0/brightness

  # Somebody else turns on the keyboard backlight
  # Wait for them before turning it off.
  sleep 1
  echo "0" > /sys/class/leds/smc\:\:kbd_backlight/brightness
end script

The sleep for the keyboard backlight control is not ideal, but it has worked every time for me.

  • I should note that the keyboard backlight occasionally turns itself back on. Not sure what causes that. – cgmb Jul 17 '14 at 4:48

Keyboard backlight is only partially implemented, I think. It's working for unity, but in KDE there's no UI for it. You can manually change the keyboard backlight brightness on the command line. I don't have a mac, so I'm not sure what the exact command is, but for my samsung, the command is

echo 5 > /sys/class/leds/samsung\:\:kbd_backlight/brightness

(you have to do this as root, you can use sudo -s)

For the mac, have a look in /sys/class/leds, and see what's there.


Has been a long time that you asked this question. I had a similar problem and solved it this way:



I believe I can help you with the screen brightness. I've posted what worked from me as an answer to a similar question on Ask Ubuntu.

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