Arch Linux

postadelmaga

Member

Registered: 2012-12-22

Posts: 5

[Dell Inspiron 14z - WMI] - Brightness FN key not working

I just installed Arch ( moving from Ubuntu ), everything works fine except the brightness key ((fn) + F4 , (fn) + F5).
The point is that those key works out of the box on Ubuntu so I guess there is a way to enable this also on Arch, so I wonder if anyone can give me some hint on how to accomplish this.

What I know/I did:

I follow this tutorial Extra_Keyboard_Keys and I saw that on Ubuntu those keys are mapped, `showkey` gives this output on keypress:
- keycode 224 press
- keycode 225 press

On Arch I cannot figure out any keycode/scancode associated to those keys ... neither with showkey, xev, acpi_listen or looking in dmesg.
So it looks like those keys are not mapped in the kernel at all.

I thought that this is relative to some kernel module and I focus my attention on dell_wmi and dell_laptop module but:
1. both modules are automatically loaded in Ubuntu and Arch
2. if I remove them in ubuntu (rmmod) the fn keys continue to work ( so I guess it is another module that is providing this functionality, I'm I right ? )

Any idea ?

Thanks,
Francesco

Last edited by postadelmaga (2013-08-25 03:33:30)

Pse

Member

Registered: 2008-03-15

Posts: 415

Re: [Dell Inspiron 14z - WMI] - Brightness FN key not working

Does manually changing the backlight through /sys/class/backlight work?

Also, you may want to try letting the EFI/BIOS handle the blacklight for you. On my Acer laptop adding

acpi_osi=Linux

to the kernel command line was enough.

Edit: missing "to the kernel command line".

Last edited by Pse (2013-08-26 00:02:42)