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Stevearch

Member

From: North Wales

Registered: 2014-04-21

Posts: 80

[SOLVED] Dell Latitude D630 backlight - Help!

Hi all!

Hope your all ok!

Im after abit of help with the backlight on this Dell laptop. I've just done a fresh install of Arch and by default my backlight is at the lowest setting. So as per the Arch wiki i followed the instructions for increasing the backlight. None of which seem to work properly. I have managed to get it working but it's abit of a work around and not permanent.

In my /sys/class/backlight i have two options: 

[stephen@Archey ~]$ ls /sys/class/backlight/
dell_backlight  intel_backlight

Now if i go into the Dell directory and change my brightness settings it has no effect what so ever on my brightness. It's Max brightness is: 7 and the current brightness is: 6. But changing this figure as i said does nothing for my brightness.

Now if i go to the Intel directory! The max brightness figure is: 255000 and on every boot the current brightness is always at that number (255000) If i go in and change it by 1 so for example: 254999 My brightness all of a sudden goes up and i can use my keyboard keys to adjust it accordingly.

But once i reboot i have the same problem. Now it does mention in the Wiki that Systemd saves my brightness settings and restores them on boot and here is where i think the confusion lies.

[stephen@Archey intel_backlight]$ systemctl | grep backlight
sys-devices-pci0000:00-0000:00:02.0-drm-card0-card0\x2dLVDS\x2d1-intel_backlight.device   loaded active plugged   /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight
sys-devices-platform-dell\x2dlaptop-backlight-dell_backlight.device                       loaded active plugged   /sys/devices/platform/dell-laptop/backlight/dell_backlight
systemd-backlight@backlight:dell_backlight.service                                        loaded active exited    Load/Save Screen Backlight Brightness of backlight:dell_backlight
systemd-backlight@backlight:intel_backlight.service                                       loaded active exited    Load/Save Screen Backlight Brightness of backlight:intel_backlight
system-systemd\x2dbacklight.slice

Should Systemd be trying to use both? Could the Dell settings be overwriting the Intel ones?

Any help is appreciated guys!

Regards, Steve

Last edited by Stevearch (2014-04-30 19:33:08)

Stevearch

Member

From: North Wales

Registered: 2014-04-21

Posts: 80

Re: [SOLVED] Dell Latitude D630 backlight - Help!

Fixed this by setting a Udev rule

#Set backlight level to max
SUBSYSTEM=="backlight", ACTION=="add", KERNEL=="intel_backlight", ATTR{brightness}="254000"

Arch wiki article for the fix