Ubuntu Brightness toggle fix for some laptops

1. open the terminal(ctrl+alt+t)
2. type the command "sudo gedit /etc/default/grub".
3. a new dialog box will open.
4. edit the line "GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"" to "GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor""
5. save the file close the editor
6. run the command "sudo update-grub"
7. and you are set, just reboot.......

ENJOY!!!!


plz hit like if it helped
If you face any kind of problem plz comment and i would love to resolve your problem........