i have repeatedly found it very difficult on desktops.
echo 40 > /sys/class/backlight/
doesn't work as there are no backlight files. in laptop too sometimes there are not there but fn key works!
so i from where does the fn key change backlight when no backlight found?
i want to follow the same method my laptop is using and able to change brightness without the backlight file.
so for desktop it should be possible via an alternate method?
i installed xbacklight but it doesn't work as there are no backlight files.
i usually use desktop where i never ever found backlight files despite installing 6 distros.
this is the o/p of xrandr -q | grep " connected"
VGA-1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 443mm x 250mm
and this is o/p of xrandr --output LVDS1 --brightness 0.5
warning: output LVDS1 not found; ignoring xrandr: Need crtc to set gamma on.
so how to use xrand wihtout any errors
and sudo setpci -s 00:02.0 F4.B=80
setpci: Warning: No devices selected for "F4.B=80".
and http://pastebin.com/gBSBsZ1w is o/p of lspci
i also did sudo setpci -s 01:00.0 F4.B=20
without any error since that is the VGA from lspci cmd. but nothing happened
echo
into a folder. In/sys/class/backlight/
there should be another directory , for example mine isacpi_video0
, where you havebrightness
andmax_brightness
file.