Screen Brightness

[chantaspell]

Hi

I am running LMDE on acer aspire 5755g. I want to be able to adjust screen brightness (not least coz the power appetite of LMDE is outrageous!).

When I do Fn+left/right arrow the on screen display shows a slider (more or less as it does in windows 7) however th brightness doesnt change. Likewise, if I go through the menu to "system settings" and "screen" the slider moves but makes no difference.

Any ideas?

Many thanks

[äxl]

I am running LMDE on acer aspire 5755g. I want to be able to adjust screen brightness

Have you looked in Windows if power consumption changes considerably?
What does xbacklight say?
Also please put the output of:

Code: Select all

grep -Ei backlight .xsession-errors
grep -Ei backlight /var/log/Xorg.0.log

And:

Code: Select all

inxi -Gx

(not least coz the power appetite of LMDE is outrageous!).

I've had success with another Aspire model lowering power consumption about a third by installing Nvidia's proprietary drivers.
I used sgfxi because it's the easiest way (http://smxi.org/site/install.htm#sgfxi) but there are other ways (http://wiki.debian.org/NvidiaGraphicsDrivers).
If you're using the Intel graphics chip look here http://wiki.debian.org/GraphicsCard#Intel and here http://intellinuxgraphics.org/
Since your model uses Optimus I'm guessing you could also use Bumblebee (http://wiki.debian.org/Bumblebee).

[Dimitrijj]

I have problem with brightness too. During start X server, backlight is set up to maximum. Why? How to prevent the backlight change on my HP Compaq 6510b?
I did try GRUB_CMDLINE_LINUX="acpi_backlight=vendor" in /etc/default/grub. But brightness keys (Fn+F9/Fn+F10) was not work in this case.
In the Ubuntu 11.10, 12.04 and OpenSuse 12.1 GRUB_CMDLINE_LINUX="acpi_backlight=vendor" work perfect. The backlight is not change (during start X server) and the brightness keys is work correctly.

[chantaspell]

Hi

Thanks for that and sorry it has taken me a while to get back onto this...couldn't get time in front of my laptop for a few days.

Here's the info you asked for

# xbacklight
55.555556

and then

# grep -Ei backlight .xsession-errors
s # grep -Ei backlight /var/log/Xorg.0.log
[ 20.892] (II) intel(0): found backlight control interface /sys/class/backlight/acpi_video0

and also

# inxi -Gx
Graphics: Card-1 Intel 2nd Generation Core Processor Family Integrated Graphics Controller Card-2 nVidia GF108 [GeForce GT 540M] X.org 1.11.4 Res: 79x24 Gfx Data:

And thanks for the power saving tips! I will check those out next

[äxl]

Here's also a discussion: https://bbs.archlinux.org/viewtopic.php ... pid=989286
C program (which you'd have to compile ...): http://coderazzi.net/linux/meego/brightness.html
And a start script: http://wiki.debian.org/InstallingDebian ... 60/Squeeze

[ukbrian]

There's also a discussion with a possible solution on this thread http://forums.solusos.com/viewtopic.php?f=21&t=779&start=20