Arch Linux

v43

Member

Registered: 2011-02-03

Posts: 140

[SOLVED] how to manage display brightness?

i found this tip
echo -n 100 > /proc/acpi/video/VGA/LCD/brightness

(from http://www.linuxscrew.com/2007/10/25/aj … dell-1501/ )

but i don't have any "video" folder in /proc/acpi/
i don't know if it's somehow related to this, but i've installed the video driver with pacman -S xf86-video-ati  as i'm running on an antique mobility radeon 6 (or something like that). it looks like it's running fine, although the performance is poorer than it's in windows

if i could run that command above, i could then make a script to call with a keyboard shortcut. or is there a smarter way?

ps-ot: how is the function key on the laptop keyboard called? i mean, the short name to put in the openbox configuration file. eg the win key is W...

thanks!

Last edited by v43 (2011-02-04 01:32:29)

lagagnon

Member

From: an Island in the Pacific...

Registered: 2009-12-10

Posts: 1,087

Website

Re: [SOLVED] how to manage display brightness?

Try "xbacklight" - it works on many laptops, but not all.

---

Philosophy is looking for a black cat in a dark room. Metaphysics is looking for a black cat in a dark room that isn't there. Religion is looking for a black cat in a dark room that isn't there and shouting "I found it!". Science is looking for a black cat in a dark room with a flashlight.

v43

Member

Registered: 2011-02-03

Posts: 140

Re: [SOLVED] how to manage display brightness?

thaks for the tip!

is it xorg-xbacklight from extra?
i can't find any documentation about it. could you give me an hint on how it works? thanks!!

running it produces: No outputs have backlight property. this has been said to be a driver issue. but in windows the brightness of my display is managed by a little app from compaq, not by the radeon drivers. i mean, i think the compaq app really works on the backlight lamp, whereas the driver can just make pixel darker, while the lamp brightness remains the same. isn't it so?

Last edited by v43 (2011-02-03 22:18:05)

skunktrader

Member

From: Brisbane, Australia

Registered: 2010-02-14

Posts: 1,587

Re: [SOLVED] how to manage display brightness?

Maybe the BIOS in your computer just doesn't expose the brightness.  You could try

find /proc -name brightness

to see if it is in a "non standard" location

v43

Member

Registered: 2011-02-03

Posts: 140

Re: [SOLVED] how to manage display brightness?

nope
there are lots and lots of "task" .. no brightness there =/

i suspect it could be the video driver that isn't fitting. i'll try with fglrx

Peasantoid

Member

Registered: 2009-04-26

Posts: 928

Website

Re: [SOLVED] how to manage display brightness?

You might find something in /sys/class/backlight or in /sys/devices/virtual/backlight. There are also a number of kernel modules that may help (modprobe -l | grep backlight).

v43

Member

Registered: 2011-02-03

Posts: 140

Re: [SOLVED] how to manage display brightness?

/sys/class/backlight
this folder's empty, the other doesn't exist

instead of the catalyst driver i tried to better configure the opensourced ones, following these advices
https://wiki.archlinux.org/index.php/ATI

i configured kms successfully, but with no results.

thanks for your help guys, i really hope we can find a workaround for this!

UPDATE: http://larve.net/people/hugo/2002/12/evo410

Adjusting brightness    Yes    Using Fn-F10 key and then the arrow keys.

believe me guys, when i read this, and checked it worked......  i felt like... like someone who've found the F13 key! lol

sorry for the useless thread
bye!

Last edited by v43 (2011-02-04 00:44:02)