Brightness control does not work in Ubuntu 14:04

Question

I have a "Inspirion 15r SE 7520" and the Brightness control doesn't work. Using amd driver, I have already added:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

to the grub config file but with this line, my Ubuntu doesn't start.

What I have to do?

Using AMD RADEON HD7700M SERIES and my notebook have Hybrid graphics.

I had a similar problem, answers from this questions helped me http://askubuntu.com/questions/450131/problem-with-adjusting-brightness-ubuntu-14-04 — ezpn, May 23 '14 at 17:52
@user284626 After editing grub config file,before reboot, have you run: sudo update-grub? this might help. — girardengo, May 23 '14 at 18:48
yes i did it xP but after this my ubuntu doesnt start any more — user284626, May 23 '14 at 18:53
I found this temporary solution :
echo 150 | sudo tee /sys/class/backlight/intel_backlight/brightness

But the FN key still doesn't working...

Any solution? — user284626, May 23 '14 at 19:32

score 0 · Answer 1 · answered Apr 09 '16 at 05:16

I have downloaded this for nvidia geforce Adjust backlight of Compaq Armada laptops (E300, M500, M700) Change LCD brightness on GeForce cards

and updated my grub file with

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"

I got it working.... :-)

1 Answers1