Having just received a new (used) ThinkPad X250 I felt somewhat lost when I realized the display brightness keys didn’t do anything in my Awesome WM setup.

My previous ThinkPads were a T430s and an X230 and it turns out Lenovo had changed from HW controlled to SW controlled in this new generation.

A quick google later and I had found Fredrik Haikarainen’s light and bound it to the approriate keys in my .config/awesome/rc.lua:

-- Brightness
globalkeys = gears.table.join(globalkeys,
  awful.key({}, "XF86MonBrightnessUp",   function () awful.util.spawn("light -A 10") end),
  awful.key({}, "XF86MonBrightnessDown", function () awful.util.spawn("light -U 10") end))

Actually, I tried running light from the command line first, without running sudo make install, and that didn’t work so I was about to give up. Turns out light needs to be SUID root because of reasons. Oh well, that we should be able fix relatively easy.

Great little tool, much recommend!