Re: extent brightness adjust in 2.6.18?

[Matthias G. <mat...@us...>]

On Wed, 27 Sep 2006 01:15:27 -0400
timotheus <pbb...@ts...> wrote:

> The 'actual_brightness' file is read-only and seems to always have the
> same value as 'brightness'.
> 
> The 'brightness' file is writable and immediately adjusts the
> LCD. Appropriate values are 0 (full dark), 1 (min. brightness), to the
> value of 'max_brightness', which is 127 on this laptop.
> 
> 'max_brightness' is the maximum value allowed to be written to
> 'brightness', otherwise an error is displayed on the terminal:

I found the same. Pbbuttons will use max_brightness and brightness.

> The sysfs brightness value *does* smoothly adjust the LCD by each
> increment from 0 to 127, as demonstrated with the command:

The release candidate of pbbuttonsd (in CVS) uses all supported
brightness levels so we don't need a transformation table or something
like that.

> One interesting note.  Pbbuttonsd 0.7.x has a bug that sometimes
> occurs by leaving the machine idle for hours and then returning to
> using it.  The display remains at maximum brightness and
> does not respond to F1/F2 adjustments until using these keys to adjust
> to full-dark, and then increasing brightness again.
> 
> When this bug is active, the display brightness value is '127'.  But,
> the maximum value pbbuttonsd sets by using F1/F2 is '120'.  I assume
> that this bug will disappear when using the sysfs interface anyways,
> but thought it interesting.

Never heard about this before.
- Was the display dimmed or completely dark before you re-using it?
- What about sleep mode? Did the machine idle all the time?
- Was the option UseFBBblank activated in your configuration?

Try to set UseFBBlank = "no". New PowerBooks were reported to have
problems with this option and I think recent kernels don't need it any
longer anyway. 

Please tell me if that behaviour is fixed with the release candidate.

  Best Regards
    Matthias