I'm using Ubuntu Mate 16.04 with ThinkPad T450s.

When I login into Ubuntu, keyboard back-light is on, then I turn it off, then after spending idle time when I touch to any key, keyboard back-light turn on again!

What should I do for disable it?


I found the keyboard-backlight brightness file path that toggles with three mode:

  • 0 is off
  • 1 is low light

  • 2 is high light

I set the brightness to 0 in rc.local as following, but it not worked:

I put the following line before exit 0 in /etc/rc.local:

  • echo 0 > /sys/class/leds/tpacpi:\:\kbd_backlight/brightness

Thanks in advance.


From https://ubuntu-mate.community/t/keyboard-light-keeps-turning-on-after-login-and-or-unlock/6914/12 I got the right direction for the solution (similar problem with Ubuntu Mate 18.10 on a ThinkPad T480s).

I edited /etc/dbus-1/system.d/org.freedesktop.UPower.conf (with sudoedit) and changed the allow in the lines

<allow send_destination="org.freedesktop.UPower"

to a deny so after editing the lines look like this:

<deny send_destination="org.freedesktop.UPower"

No service restart or reload necessary, works directly after changing the file. Manual switching of the keyboard backlight with the hotkey (Fn+Space).


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