Disable Fn-keys brightness change on Dell Inspiron E1405

Question

I've got an old Dell E1405 which smoothly runs 14.04, with one caveat that is.

When I press the Fn button with arrow-up or arrow-down, the brightness jumps in huge steps.

Is there a way to disable this? So that the brightness is only adjusted by the hardware (I would believe that the BIOS adjusts it because prior to system startup, I can also change brightness)

Any help would be appreciated.

Thank you.

Answer 1

It may help to set acpi OS and vendor in the bootloader by editing grub.cfg, as mentioned here, by adding this:

acpi_osi=Linux acpi_backlight=vendor

To the GRUB_CMDLINE_LINUX_DEFAULT line in /etc/default/grub. You then need to run sudo update-grub and reboot to make the changes.

This I find works on a few machines, to get brightness to be less jumpy etc