I have installed GNOME Manjaro on a iMac 27 (mid 2011) with a Radeon HD 6770M graphic card.
Although most of the thing are working I cannot change the brightness using the keyboard buttons nor the brightness slider.
I chose the free drivers during the installation of Manjaro
Because there are many suggestions on how to solve this issue, I would like to have a simple clear solution and avoid breaking the installation.
Also, I am wondering if it is really required to modify GRUB and if that might break the installation.
While this one suggests to add the following lines to the GRUB configuration
acpi_backlight=video acpi_backlight=vendor acpi_backlight=native
Which one would you suggest?
Do I really need to add the Kernel parameters?
Should I use free or proprietary drivers?
Sorry for the many questions to a maybe simple issue.
Thanks everybody in advance!