Backlight cycles between values

Thanks for providing this - its nice to have these features. Just built 2.3.1 and was happy to see lightum can now manage the backlight too.

However, on my MacBook Air (5,2) when run in auto mode it just cycles the backlight between values, resetting it at each poll interval, thus the screen cycles bright - dim - bright. Almost working! Keyboard brightness work fine.

Any suggestions on how I might fix this? I'd live to have the backlight auto adjust.

 ~ ⮁ lightum ⮀ master ⮀ $ ⮀./lightum -f -v -w 2 -d 2 -i 3
CONFIG:
        manualmode: 0
        ignoreuser: 1
        ignoresession: 0
        workmode: 2
        queryscreensaver: 0
        maxbrightness: 255
        minbrightness: 0
        maxbacklight: 15
        minbacklight: 1
        polltime: 300
        idleoff: 3
        screenidle: 30
        fulldim: 0

lightum v2.3.1 running in auto mode 
Error org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SettingsDaemon was not provided by any .service files
light_sensor: 7 light_avg: 7 idle_time: 0.072000 auto mode backlight: 6/15 
current backlight: 15
-> set screen backlight: -1 -> 6

light_sensor: 7 light_avg: 7 idle_time: 0.620000 auto mode backlight: 6/15 
current backlight: 15
-> set screen backlight: 15 -> 6

light_sensor: 7 light_avg: 7 idle_time: 1.261000 auto mode backlight: 6/15 
current backlight: 15
-> set screen backlight: 15 -> 6

poliva / lightum

Backlight cycles between values #23