I have kde desktop environment, and Fn + F3 / F4 buttons cannot change keyboard brightness.
I also assign other keys to increase or decrease keyboard brightness in global shortcuts menu, but its not work again.
So I try to change brightness level by this command:
echo 3 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness
And keyboard brightness change successfully.
But kde uses dbus to change keyboard brightness, So I try to use this command (which can be found in Arch wiki):
dbus-send --type=method_call --print-reply=literal --system --dest='org.freedesktop.UPower' '/org/freedesktop/UPower/KbdBacklight' 'org.freedesktop.UPower.KbdBacklight.SetBrightness' int32:2
But brightness not changes at all and I got this error:
Error org.freedesktop.DBus.Error.UnknownMethod: No such interface “org.freedesktop.UPower.KbdBacklight” on object at path /org/freedesktop/UPower/KbdBacklight
So I try change permission of that file:
sudo chmod 666 /sys/class/leds/asus::kbd_backlight/brightness
But I can't change keyboard brightness by Fn + F3 / F4 or dbus again.
Fn + F3 or F4 keys combinations works well and I can see signal sends well:
$ xev | sed -n 's/^.*state \([0-9].*\), keycode *\([0-9]\+\) *\(.*\), .*$/keycode \2 = \3, state = \1/p' keycode 237 = (keysym 0x1008ff06, XF86KbdBrightnessDown), state = 0x10 keycode 237 = (keysym 0x1008ff06, XF86KbdBrightnessDown), state = 0x10 keycode 238 = (keysym 0x1008ff05, XF86KbdBrightnessUp), state = 0x10 keycode 238 = (keysym 0x1008ff05, XF86KbdBrightnessUp), state = 0x10
So how can I change keyboard brightness with dbus?