Comment 34 for bug 1653456

I added requested option to /etc/default/grub:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash asus-wmi.dyndbg=+p asus-nb-wmi.dyndbg=+p"
After that I executed "update-grub" to update the changes and then rebooted.

I pressed all of the Fn keys in the following order:

(FUNCTIONAL)
Fn+F1
Puts the Notebook PC into Sleep mode
Fn+F2
Turns Airplane mode on or off
Fn+F3
Decreases brightness for the backlit keyboard
Fn+F4
Increases brightness for the backlit keyboard
Fn+F5
Decreases display brightness
Fn+F6
Increases display brightness
Fn+F7
Turns the display panel on or off
Fn+F8
Toggles the display mode
Fn+F9
Enables or disables the touchpad

(NON-FUNCTIONAL)
Fn+F10
Turns the speaker on or off
Fn+F11
Turns the speaker volume down
Fn+F12
Turns the speaker volume up

Here's attached my DMESG output.