Q:

Backlight adjustment not working in Lenovo IdeaPad Y580

I installed Ubuntu 13.04 on my Y580, and I added the acpi_backlight=vendor option to the bootloader. The OS boots without the black screen now, but I can't adjust the brightness with Fn+Up/Down keys. Is there any solution for this?

A:

Alright solved this on my own.

Open file /etc/default/grub.
Find a line GRUB_CMDLINE_LINUX="" (there might be something between the quotes).
Add acpi_osi=Linux between the quotes, so the result might be something like GRUB_CMDLINE_LINUX="acpi_osi=Linux"
Run sudo update-grub

