Start your system and wait for the GRUB menu to show. Now highlight the kernel you want to use, and press the 'c' key. You should be able to see and edit the commands associated with the highlighted kernel. Go down to the line starting with linux and add your parameter acpi_osi=Linux to its end. Now press Ctrl + x to boot. When your screen goes black again press fn keys for changing the brightness (try both of them, increasing and decreasing brightness, multiple times). If that worked this is how you permanently add that parameter to the kernel so you don't need to go trough the same procedure every time you boot:
Go to terminal and run this:
sudo nano /etc/default/grub
Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT and append acpi_osi=Linux to its end. For example:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux"
To save the file press 'Ctrl+X' and then 'y'. Now, in order to changes take effect you need to update grub:
That is it. Enjoy it!