Re: [gentoo-user] How to dim the display brightness

["Sebastian Günther" <samson@guenther-roetgen.de>]

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* Damian (damian.only@gmail.com) [23.02.09 19:21]:
> On Mon, Feb 23, 2009 at 1:03 PM, Sebastian Günther
> <samson@guenther-roetgen.de> wrote:
> > * Damian (damian.only@gmail.com) [23.02.09 10:19]:
> >> Hi,
> >>
> >> I cannot find the way to dim the brightness of the display on my
> >> laptop. It doesn't seem to be nothing useful in /proc/acpi neither I
> >> can find anything in google.
> >>
> > Did you enable the apropiate acpi drivers in the kernel? They depend on
> > your laptop model...
> Yes. But nothing seems to work.
> 
acpi_os-name = "Linux" as kernel parameter might help.

and take a look if /sys/class/backlight/acpi_video0/ is present:
this is the kernel interface to set the brightness.

CONFIG_BACKLIGHT_LCD_SUPPORT

is the appropriate kernel config category to look at in recent kernels.

BTW which kernel are you using?

> I can do it by using nvidia settings, but the dimming is different
> from the one you get when pressing Fn + the dimming keys on a text
> console 
No doubt: the first dimms the videocard output, the latter the LCD.

>(btw, this is a weird behavior: I cannot do key-based dimming
> when X is running).

I think that the Xserver catches this before reaching the hardware.

You can use xev to see which keycode is emmitted and then look in your 
desktop environment if this is match with some action.

> 
> > http://www.gentoo.org/doc/en/power-management-guide.xml
> Yep, I looked there, but the example don't apply to my laptop model :(
> 
Well. it should be somehow applicable, because it is rather generic.

> Thanks.
> 

HTH
Sebastian

-- 
 " Religion ist das Opium des Volkes. "      Karl Marx

 SEB@STI@N GÜNTHER         mailto:samson@guenther-roetgen.de

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