Can't change backlight after installing AMD 14.12 driver

[lakistrike95]

Hello,
I have a problem, finally i installed AMD driver, latest version, with previous version i've had some problems, but now it's working, but i can't change backlight, i was changing /etc/default/grub file, and didn't change anything. Hotkeys are not in function, and when i change brightness in battery menu it is same, it's everything same, no changes
I tried to change backlight file and it says permission denied, i loged like root and change value, but there is no difference.
I changed line in grub and lost brightness menu in battery, i changed this line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to look like this "GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linuxacpi_backlight=vendor"".
And still i have same problem.
Anyone to help?

[oshunluvr]

Can we assume the missing space between Linux and acpi is a typo in your post and not in your boot line?

[lakistrike95]

I've made mistake in typing in my post, i have space in boot line.
And i forgot to say, my laptop is Toshiba Satellite C50D-A-10U.

[Teunis]

I know AMD is not nVidia but in the latter's case it can be fixed by creating an /etc/X11/xorg.conf file containing:

     Section "Device"
        Identifier    "Default Device"
        Option "RegistryDwords" "EnableBrightnessControl=1"
        Option    "NoLogo"    "True"
    EndSection

Or go to a terminal (Ctrl+Alt+F4) and use the brightness keys form there.

I repeat, this it what works on nVidia.

[lakistrike95]

It's not working.