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pordzio

Member

From: Rzeszów/Poland

Registered: 2011-07-05

Posts: 6

[SOLVED] Samsung R580 backlight

Hi guys!

I'm trying to get backlight buttons to work under XFCE.

I got to the stage, where

echo VALUE > /sys/class/backlight/nvidia_backlight/brightness

changes backlight intensity.

And now. How to make XFCE's brightness plugin work (and I believe Power Manager's brightness function will also start working)

It doesn't say "No device", but there's no effect changing it's value.

Now I've read, that adding

Option "RegistryDwords" "EnableBrightnessControl=1"

to xorg.conf is enough to make it work.

Cheers and thanks for your help.

Where and how should i add this line, when I don't have an xorg.conf file. Everything is done by Udev.

I can provide dmesg, lspci, lsmod and uname outputs on demand.

Last edited by pordzio (2011-07-13 08:15:08)

MrCode

Member

Registered: 2010-02-06

Posts: 373

Re: [SOLVED] Samsung R580 backlight

I happen to have this same laptop model, and I was able to get backlight level adjustment working a little differently:

I made two small shell scripts, caled ".brt_up.sh" and ".brt_dn.sh" in my ~:

.brt_up.sh:

#!/bin/bash

LEVEL=`cat /sys/class/backlight/acpi_video0/brightness`

if ((LEVEL <= 7)); then
    ((LEVEL += 1))
fi

echo $LEVEL > /sys/class/backlight/acpi_video0/brightness

.brt_dn.sh is basically the same, except it checks if $LEVEL is greater than 0 before lowering it.  Of course, you may have to modify it a little to suit your needs…

The file in /sys/class/<...> is made writable on every boot with a chmod line in rc.local.

Then I went into the Xfce keyboard settings and mapped executing these two scripts to XF86MonBrightnessUp/Down.

Hope this helps.

pordzio

Member

From: Rzeszów/Poland

Registered: 2011-07-05

Posts: 6

Re: [SOLVED] Samsung R580 backlight

Problem solved.

I created file "/etc/X11/xorg.conf.d/99-nvidia.conf" where i put

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
        Option "RegistryDwords" "EnableBrightnessControl=1"
        Option "EnableBrightnessControl" "1"
#       Option "NoLogo" "True"
EndSection

And backlight settings with xfce4-brightness-plugin works