Enable the keyboard backlights on supported Lenovo (e.g. Carbon X1) with command

Some Lenovo laptops have keyboard backlights, and they can be turned on using Fn + Space. There are three states: off, normal and bright.

When I start Ubuntu, these laptops always default back to a burning sun screen brightness and the keyboard lights off.

I want a medium brightness and keyboard lights on by default, because I usually use this laptop in dark environments.

The backlight is easy. Internet is filled with information about this.
echo 10 > /sys/class/backlight/acpi_video0/brightness

But how do I turn on the keyboard backlights with a command? I've been looking here but it seems to do nothing:
/sys/class/leds/tpacpi\:\:thinklight

Updates

I tried for i in {1..32}; do xset led $i; done but nothing changes. Perhaps the keyboard backlight for Lenovo laptops has a proprietary driver and can only be controlled through tpacpi?

Also tried for i in $(find /sys/devices/platform/thinkpad_acpi/leds/ | grep /brightness\); do echo 255 > $i; done of no avail.

Solution 1:

This is really needed to be fixed!

I think this is a common bug in new thinkpads. If you light keyboard manually fn + space then executed:

echo 0 > /sys/class/leds/tpacpi\:\:thinklight/brightness

keyboard will fade out. Please see the following link if it helps:

http://www.spinics.net/lists/ibm-acpi-devel/msg03090.html

Solution 2:

Looks as this has been updated, my X1C with ubuntuMATE 16.04 LTS has

/sys/class/leds/tpacpi\:\:kbd_backlight/brightness

which works as expected ie:

# echo 2 > /sys/class/leds/tpacpi\:\:kbd_backlight/brightness

Brings it to full light :)

Solution 3:

This is the bash script I use:

https://gist.github.com/vzaliva/0adba7bc40e2f31a0b5f802af2a63267

Works on IBM ThinkPad X260 with Ubuntu 16.04.