Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

want to control the brightness (which is by default set to 100%). I want to lower it down because its killing my battery life and drains it out in matters of seconds. I cannot control the brightness using fn keys and other control provided in backtrack 5 o/s.


  • Ubuntu Description: Ubuntu 10.04.2 LTS Release: 10.04 Codename: lucid

  • Model Inspiron N5110

  • kernel Linux bt

lsmod | grep dell:

dell_rbu                5691  0 
dell_wmi                1413  0 
sparse_keymap           3194  1 dell_wmi
dell_laptop             7700  0 
wmi                     8772  1 dell_wmi
dcdbas                  5557  1 dell_laptop
rfkill                 14987  3 dell_laptop,cfg80211,bluetooth
share|improve this question

switch to latest release 11.10 I am using it no problems so far all Fn keys brightess touch pad volume are working a ok.

I own Dell N5110 and using it as my primary machine with ubuntu 11.10

share|improve this answer

If you run

lsmod | grep dell

Do you see "dell-laptop" and "dell-wmi" there?

If not, try to modprobe them:

sudo modprobe dell-laptop dell-wmi
share|improve this answer
ok let me past the output – asadz Nov 9 '11 at 15:35
Hmm, what kind of graphics card do you have? lspci | grep VGA – Chris Wayne Nov 9 '11 at 16:46
lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 01:00.0 VGA compatible controller: nVidia Corporation Device 0df5 (rev a1) – asadz Nov 9 '11 at 17:01

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.