I have a dual boot system (Ubuntu 18.04/Win7) on my Sony Vaio (SVE1711R1E) which i recently upgraded from Ubuntu 17.04. After the upgrade the keyboard backlight is turned off by default after first login (it's on during boot screen) and turns on only after wake up from suspension.
This turn on might has as a cause the "allow" option mentioned here, which i confirmed on my system.
I have added a sony-laptop.conf file under /etc/modprobe.d/ with content "options sony-laptop kbd_backlight=1" (as mentioned here but nothing changed). I can also confirm that there is no sony-laptop folder under /sys/class/leds/ as mentioned here nor that there are kbd_backlight system files under /sys/devices/platform/sony-laptop.
However, the only kbd_backlight files i found are under /sys/module/sony_laptop/parameters and therse are a kbd_backlight with value 1 and a kbd_backlight_timeout with value -1.
What changes should i make in order to have backlight turned on by default?