Display brightness cannot be changed: OpenSUSE 12.2, Dell Inspiron 7520

English Hardware
1

I recently installed both Ubuntu 12.10 and OpenSUSE 12.2 64-bit, KDE, the two OSs sharing a new Dell Inspiron 7520 laptop. This laptop has an AMD Radeon HD 7730M graphics card. I installed fglrx64_xpic_SUSE122.

My problem is that the brightness controls (Fn+F4 and Fn+F5) do not work under OpenSUSE, (but work perfectly under Ubuntu). All the rest of the Fn+Fx buttons (e.g., volume control, wireless on/off, etc) seem to work well for both OSs.

Running xbacklight (e.g. xbacklight -dec 20) doesn’t change a thing – this command did not change display brightness. Adding “acpi_backlight=vendor acpi_osi=Linux” to the GRUB2-EFI Boot Loader options didn’t work as well.

Any suggestions on what I can do to activate the brightness controls on my laptop’s keyboard? Thanks!

2

I discovered that I can manually change the brightness by

echo 3500 > /sys/class/backlight/intel_backlight/brightness

where the number 3500 can be replaced by a number up to 4882, 4882 corresponding to max_brightness.

How can I tell my Fn+F4/F5 brightness control keys to do this command?

Also, I am using AMD Radeon HD 7730M graphics card with fglrx64_xpic_SUSE122 installed. But adjusting the brightness manually lies under a directory named “intel_backlight” (changing brightness under the acpi_video0 and acpi_video1 directories do not work). Any hints on what I may have done wrong? Any help will be appreciated.

3

Usually most Intel stuff is added to the kernel so that the user can adjust it using specific commands.

Did you try experimenting with the KDE daemon that controls the brightness?

Navigate to:

  • Configure Desktop –> Shortcuts and Gestures –> Global Keyboard Shortcuts –> KDE component
  • Click on the dropdown arrow and select KDE Daemon
  • Click on “Monitor Brightness Up” and select Custom
  • Click ‘once’ on the “None” button and add your shortcut key combo for increasing the screen brightness
  • Repeat with decreasing the brightness

Click on the Apply button to confirm your changes
Log out, shutdown and restart your laptop

Try out your brightness increase and decrease button combos.

4

Due to a kernel regression, I was using the same workaround that Romanator described. It wasn’t possible to use the fn +f9 and fn + f10 key combo though (because the fn key wasn’t captured) so I was using CTRL + f9 and CTRL + f10 instead. A recent kernel update seems to have fixed the problem for my Compaq 6710b.

5

Try Configure desktop - Input devices - Keyboard, set it to the Dell Inspiron 6xxx/8xxx. That should bring the Fn keys alive.

6

Follow Up

If the steps do not work with the kernel provided with openSUSE 12.2, I would recommend downloading from download.opensuse.org a kernel v5x or higher.

This topic severely needs a help file sticky.

7

great sugession , that worked for dell inspiron 5521…thx