I have an HP Pavilion g6 and can't adjust the brightness. I have specific buttons for this on my keyboard, but they are not working. Tried in System Settings too, but even if I change the brightness there nothing is happening. Tried through the terminal too but it did not work. Any ideas anyone?
According to this thread, a user solved his problem with Kamal Mostafa's PPA. But, this PPA is no longer supported and point out another one. Again, there is an explanation saying that Oneiric already includes this kernel. But, on some systems a boot parameter is still needed:
So, before you boot your system via Grub, just press "e" and put
acpi_backlight=vendor at the end of kernel line. And start your system with Ctrl+X. If that works, edit your Grub file for permanent solution.
gksudo gedit /etc/default/grub
Change this line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
and update grub: