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The brightness shortcuts via fn key don't work.

I tried each solution from this answer and its comments. After editing /etc/default/grub file I rebooted.

GRUB_CMDLINE_LINUX="acpi_osi=Linux"
GRUB_CMDLINE_LINUX="acpi_backlight=vendor"
GRUB_CMDLINE_LINUX="acpi_osi=linux acpi_backlight=vendor"
GRUB_CMDLINE_LINUX="acpi_osi_Linux"

What other workarounds/solutions are there?

Relevant output:

$ sudo lshw -C display
  *-display UNCLAIMED     
       description: 3D controller
       product: GK107M [GeForce GT 750M]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: latency=0
       resources: memory:f6000000-f6ffffff memory:e0000000-efffffff memory:f0000000-f1ffffff ioport:e000(size=128) memory:f7000000-f707ffff
  *-display
       description: VGA compatible controller
       product: 4th Gen Core Processor Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 06
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:50 memory:f7400000-f77fffff memory:d0000000-dfffffff ioport:f000(size=64)
share|improve this question
    
Which GPU do You have? –  Kai May 25 '14 at 14:14
    
@Kai I added relevant info in the question. –  Ionică Bizău May 25 '14 at 14:46
    
Here's couple of my workarounds. Hope you may find it useful –  Serg Apr 1 at 13:51

4 Answers 4

up vote 4 down vote accepted

In the terminal:

  1. sudo gedit /etc/default/grub

    Change

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
    

    to

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="
    

    Then, save the file.

  2. sudo update-grub

  3. Restart computer.


The function keys (Fn+F5/F6) should now be active.

I found out that the grub file got modified after an upgrade of the system and had to do it again.

share|improve this answer
    
Thanks a lot! This solved the issue. Finally! :) –  Ionică Bizău Apr 20 at 5:16
    
The acpi_osi= solution got the popup to display when I hit the function keys, but now the range it from full to one tick down from full (ie, still bright). But closer than the other solutions listed by the OP. –  srlm May 19 at 3:31
    
To get the full range on the brightness (after getting it to display in the first place) adding a 20-intel.conf file worked for me: itsfoss.com/fix-brightness-ubuntu-1310 –  srlm May 19 at 3:39
    
This worked for me on my ASUS Q550LF! Thank you so much! –  Ryan Stull Jun 23 at 2:19
    
This solution only worked for me after I also removed "acpi_backlight=vendor" which I had added from another potential solution. –  Sparr Jul 17 at 14:48

It seems to me that you do not have the proprietary NVIDIA-Driver installed. If this is true you could try to install this driver using the pre-installed program 'Additional Drivers'. This should work in Ubuntu 14.04, but is likely to cause trouble in previous versions of Ubuntu without some additional software installed. So in case you do not use Ubuntu 14.04, please do not install the proprietary driver without further reading.

When the driver is installed and the brightness control still doesn't work you can try to run sudo nvidia-xconfig to generate a xorg.conf-file. Then you can edit this file using sudo gedit /etc/X11/xorg.conf and add the line

Option "RegistryDwords" "EnableBrightnessControl=1"

to Section "Device".

share|improve this answer
    
I won't install any proprietary drivers on my computer... –  Ionică Bizău May 25 '14 at 19:49

Now when you say the brightness keys don't work, do you see a bar moving indicating that you are changing the brightness or does pressing the FN keys do nothing at all?

share|improve this answer
    
No, the brightness is not changes and no bar is showed in UI. –  Ionică Bizău May 25 '14 at 15:13

To Reduce brightness follow this:

Open System Settings > Brightness & lock

From there control ur brightness

You can try this :

https://apps.ubuntu.com/cat/applications/brightness-controller/

IF u want to change brightness through keys Follow this :

sudo apt-get install xbacklight xbacklight -set 50

Then open Settings>keyboard>shortcuts

Add custom shortcut keys and enter following commands there: enter image description here

xbacklight -dec 10

xbacklight -inc 10

share|improve this answer
    
I know how to modify the brightness (from UI and from xbacklight) . Also, I cannot map custom shortcuts on fn key. I already tried this. :-( –  Ionică Bizău May 25 '14 at 15:16
    
Don't use the fn key use something else –  Tejas Ghalsasi May 25 '14 at 15:26
    
ALT+F5, ALT+F6 were already set, but I want the fn key to work... –  Ionică Bizău May 25 '14 at 16:30

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