My laptops is MSI GE60 2QD apache, i use dual boot to install Fedora 22 beta and yum upgrade already, but i still can't adjust my screen brightness. I have no problem to adjust brightness on Window 8.
Following is the output of xrandr:
[kelvin@apache ~]$ xrandr --verbose
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 (0x181) normal (normal) 0mm x 0mm
Identifier: 0x180
Timestamp: 88929
Subpixel: unknown
Clones:
CRTC: 0
CRTCs: 0
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
_MUTTER_PRESENTATION_OUTPUT: 0
1920x1080 (0x181) 159.667MHz *current
h: width 1920 start 0 end 0 total 1920 skew 0 clock 83.16KHz
v: height 1080 start 0 end 0 total 1080 clock 77.00Hz
[kelvin@apache ~]$
No difference even if i use xbacklight to set different value:
[kelvin@apache ~]$ xbacklight -set 10
[kelvin@apache ~]$ xbacklight -set 0
[kelvin@apache ~]$ xbacklight -set 100
[kelvin@apache ~]$
I tried xrandr but i can't set output because i can't even get the name from xrandr output above:
[kelvin@apache ~]$ xrandr --brightness 0.7
xrandr: --brightness must be used after --output
Try 'xrandr --help' for more information.
[kelvin@apache ~]$
This is the screenshot of my gnome panel(my laptop not support wayland): http://i58.tinypic.com/av6gyu.png (i don't have enough reputation to upload image)
As you can see, there's only volume control but no brightness control.
Any help will be appreciated,
you need to use:
xrandr --listactivemonitors
to see your active monitor(s) this is my case:
Monitors: 3
0: +*eDP1 1366/340x768/190+0+0 eDP1
1: +DP1 1920/520x1080/290+1366+0 DP1
2: +HDMI1 1920/520x1080/290+3286+0 HDMI1
after that you need to use:
xrandr --output <monitor> --brightness <value>
for change screen brightness.