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LucasHC

Member

Registered: 2016-07-12

Posts: 4

[SOLVED] [GNOME] Use intel_backlight instead of acpi_backlight0?

Hello there,

On my laptop I have two GPUs, one intel gpu and one discrete radeon gpu. For both of them I have loaded the kernel modules, i915 and radeon. But now the problem is that in GNOME using the Fn-keys for brightness control, nothing happens. In /sys/class/backlight, I have acpi_video0, acpi_video1 and intel_backlight. I made an xorg config file to make sure that xorg uses the intel_backlight, because this gpu is connected to LVDS. if I use xbacklight there is no problem with setting the brightness.

GNOME uses /usr/lib/gnome-settings-daemon/gsd-backlight-helper to set the brightness, if run /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness 100 myself I get the following output:

Could not set the value of the backlight: writing '100' to /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0 failed

Output of cat /var/log/Xorg.0.log | grep -i backlight:

[  1573.673] (**) intel(0): Option "Backlight" "intel_backlight"
[  1573.686] (**) intel(0): Found backlight control interface intel_backlight (type 'raw') for output LVDS1

How do I get GNOME to use intel_backlight?

Thank you!

Last edited by LucasHC (2016-07-13 09:14:09)

ooo

Member

Registered: 2013-04-10

Posts: 1,638

Re: [SOLVED] [GNOME] Use intel_backlight instead of acpi_backlight0?

You should be able to disable the acpi backlight with acpi_backlight=none: https://wiki.archlinux.org/index.php/Ba … ne_options

LucasHC

Member

Registered: 2016-07-12

Posts: 4

Re: [SOLVED] [GNOME] Use intel_backlight instead of acpi_backlight0?

Thank you!
That fixed it!