Arch Linux

addy

Member

Registered: 2011-11-16

Posts: 29

Cannot control screen brightness in GNOME 3.10

I've a strage problem regarding brightness control. I am not able to change brightness either with slider in settings or the fn keys.
I searched the forums but didn't found something relevant for my problem, others have reported that the slider works but not the fn keys. My problem is different.

After some digging, this is what I found:
Both the fn keys and brightness slider are doing (their) job. They change the value in

/sys/class/backlight/acpi_video0/brightness

but that doesn't have any effect. Under /sys/class/backlight I have two folders - acpi_video0 and intel_backlight. So if I do something like

echo 305 > /sys/class/backlight/intel_backlight/brightness

then it affects the brightness.

So I want to know why is this weired behaviour and how can I make sure GNOME handles the brightness correctly.

I think it should be a bug in GNOME settings.

Here is what I'm using:
Acer ASPIRE E1-571 with Intel Core-i3 processor and Intel HD Graphics. I've xf86-video-intel installed.

Last edited by addy (2013-12-25 03:07:03)

toz

Member

Registered: 2011-10-28

Posts: 513

Re: Cannot control screen brightness in GNOME 3.10

Since the intel_backlight interface appears to be the active one, have you tried forcing X to use intel_backlight as per the /etc/X11/xorg.conf.d/20-intel.conf hack as documented in the Intel Graphics wiki?