First, searched a lot through the web, and answers don't work for Macbook Pro 2015 (exact model is
For instance that answer has no effect on my MBP.
pommed (written in 2012).
This question resembles some older questions, but is related to newer MBP models.
Note that if you got the keyboard backlight working and wonder what MBP version you have, enter
sudo dmidecode -s system-product-name
Note also that besides keyboard backlight, everything Ubuntu 16.04 on MBP 2015 works great!