Changing brightness on a Sony Vaio laptop

Question

I just installed Ubuntu 10.10 on a Sony Vaio laptop. The brightness functions keys don't change the brightness. When I try to change the brightness I can see the levels going up and down in the notification bubble but it doesn't actually change the brightness. Is there any way to fix this?

Answer 1

When you open your Ubuntu just connect it to internet and open 'Additional Drivers' application. Then it shows available graphics drivers for your system. You can install from there and it will be fine.

Answer 2

This text was initially in Spanish.

I worked in Fedora 17. You should open /etc/X11/xorg.conf.

Must add the line:

Option "RegistryDwords" "EnableBrightnessControl = 1"

Example:

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    Option     "RegistryDwords" "EnableBrightnessControl=1"
    Option     "NoLogo" "True"
EndSection

Answer 3

The solution for me was to edit the /etc/X11/xorg.conf file. It's a problem with the graphics driver not the keymap.

Open the file for editing and add the line

Option     "RegistryDwords" "EnableBrightnessControl=1"

in the Section "Device" section as shown below.

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    Option     "RegistryDwords" "EnableBrightnessControl=1"
    Option     "NoLogo" "True"
EndSection

Answer 4

These shortcuts are controlled by the udev subsystem.

In technical terms, all shortcuts are defined in /lib/udev/keymaps. For example, for a standard Sony laptops, the file is /lib/udev/keymaps/module-sony (new Sony laptops).

0x06 mute # Fn+F2
0x07 volumedown # Fn+F3
0x08 volumeup # Fn+F4
0x09 brightnessdown # Fn+F5
0x0A brightnessup # Fn+F6
0x0B switchvideomode # Fn+F7
0x0E zoom # Fn+F10
0x10 suspend # Fn+F12

For your case you may have to create a module-mysony and add any changes there.

The link between laptop model and shortcut details is the file /lib/udev/rules.d/95-keymap.rules. Currently, there are two rules, for newer and older Sony laptops,

ENV{DMI_VENDOR}=="Sony*", KERNELS=="input*", ATTRS{name}=="Sony Vaio Keys", RUN+="keymap $name module-sony"

# Older Vaios have some different keys
ENV{DMI_VENDOR}=="Sony*", ATTR{[dmi/id]product_name}=="*PCG-C1*|*PCG-K25*|*PCG-F1*|*PCG-F2*|*PCG-F3*|*PCG-F4*|*PCG-F5*|*PCG-F6*|*PCG-FX*|*PCG-FRV*|*PCG-GR*|*PCG-TR*|*PCG-NV*|*PCG-Z*|*VGN-S360*|*VGN-SZ2HP_B*", ATTRS{name}=="Sony Vaio Keys", RUN+="keymap $name module-sony-old"