Sunday, March 28, 2010

Fixing brightness controls

The brightness controls via Fn+F5 and Fn+F6 doesn't work properly. It's more like unpredictably cycling through various levels instead of going from brighter to darker or vice versa. The issue has already been reported:

I added "acpi_osi=Linux" to the kernel options and it worked for me. Although dimming when idle doesn't work and the on screen notification doesn't work either.

So I added the also "acpi_backlight=vendor" to the kernel options and now everything works. Auto dimming and notification, too.
  1. sudo gedit /etc/default/grub
  2. find the line starting with GRUB_CMDLINE_LINUX_DEFAULT
  3. add "acpi_osi=Linux acpi_backlight=vendor" to the options
  4. sudo update-grub2
  5. reboot


  1. Thanks, this was easy and works great

  2. Danke, bestens!


  3. Much Thanks! Your page was the end of a loong search :)
    Works fine - also on screen notification works on my laptop with your fix.
    Thanks a lot!

  4. Works just fine, Thanks Olaf.

    One thing I could not solve is that oowriter crashes when using the proposed kernel. Can anybody confirm that?


  5. Thank you, man!

    Onscreen notification also works fine in my EeePC, except that now it can't reach the dimmest level (which I don't care).



  6. awesome, thanks

  7. Perfect! Made my machine usable at last. Thanks.

  8. For Fedora users, I got this EEEpc fix to work by

    1. sudo gedit /boot/grub/grub.conf
    2. add acpi_osi=Linux acpi_backlight=vendor to the end of the kernel /vmlinuz-**** lines.

    Works great again!

  9. For me (Eee PC 1005PE) this line has the opposite effect,
    "acpi_osi=Linux" makes Fn+F10-12 usable
    "acpi_backlight=vendor" makes it impossible to get max. brightness.
    I removed the 2nd line updated grub, now the OSD notification for brightness disappeared

  10. @Alex 1005P has really different hardware, so you cannot use the fixes from this blog for this machine.

  11. I can also confirm it works, with no problems with OO writer.


  12. Hi, I've just tried this grub update, but nothing happens after I reboot, brightness controls are just the same...can you help please?

  13. @jack please check if this solution is right for you.
    - ubuntu 10.04 lucid lynx 32 bit
    - EeePC 1001p

  14. Olaf, thanks for your reply, I am indeed running ubuntu 10.04 lucid lynx on Asus EeePC 1001p

  15. I downloaded and installed Ubuntu 11.04 on my Netbook, a white Asus Eee PC 1005PE.

    At first, I had exactly the same backlight problems as mentioned here - but ...

    thanks to Olaf (!) and his great instructions it worked!

    For all starters,
    if you open the terminal with Ctrl+Alt+T make sure to type the command as mentioned above.

    The Terminal will ask for your password which is the password you set up for your user when Ubuntu starts. Do not worry that the password does not show up - once you click Enter ..

    and the password was correct,
    it will allow you to make the changes in the kernel options.

    Just make sure to follow this guide step by step :-) Thank you, Olaf! You helped me a lot!

  16. Hi Olaf I'm running 10.04.2

    The relevant line says...


    Do i erase the "quiet splash part" or do i add your command at the end?

    If i add your command at the end, do i use separate quotation marks or enclose it in the same quotation marks as "quiet splash"?

    As you have probably noticed, i'm a bit nervous editing the file.

    Thanks in advance


  17. Hi Olaf

    No need to answer that, i found the answer in the link you provided.

    I now have a bright display and no longer need to find a dark corner to work in.


  18. You saved my eyes. It works with Dell Inspiron mini 12 and Ubuntu Lucid lynx.

  19. its not working in my laptop toshiba C665-L5011
    with Ubuntu 12.04 LTS

    any one knows how to solve in this laptop

  20. Hello, can somebody PLEASE tell me how to get into/change grub? I downloaded Ubuntu 12.04 on my Acer Aspire 5734z laptop and it installs but choosing it frustrates me when the screen never works. PLEASE help me out, I'm not a big computer person so I don't understand much.

  21. Thanks!!
    Worked perfectly on an Asus 1005PE running CrunchBang Waldorf!!!
    I've been searching for this fix for a long time! I got this problem with several distros.

  22. Thank you, Olaf !!!
    Worked on my 1005PE running Debian 7.2 :)

  23. Thanks again Olaf. My netbookused to run Ubuntu 10.04 Gnome OK but was slow with 12.04 Unity. So it now has Lubuntu 13.10 and runs well but needed the brightness problem fixed. Your fix worked perfectly.

  24. Cheers chap. Your post and the associated link solved my problem with an Asus EEE PC 1005P running Mint14. I'd put Mint on for my partner and the brightness was the only real issue. Thank you very much.

  25. thanks yooo, helped a lot, my eee pc 1005p was dark before, now its bright, i can use my fn keys but but not for brightness, it just stays at full brightness which is okay for me. but speaker fn keys work well now.