[PATCH] Fix Macbook Addon to work after resume

[David Zeuthen]

On Mon, 2007-06-04 at 11:42 -0400, Ryan Lortie wrote:
> 1) gnome-power-manager running at all.
> 
> 2) gnome-power-manager always implementing this feature.  maybe in the
> next version you decide that you don't want to do it anymore. :)

I think whatever policy agent running in the desktop session (be it
gnome-power-manager, kpowersave or whatever) needs to be smart about
things _anyway_: e.g. set the preferred brightness when the desktop
session becomes active again. Just think about fast-user-switching; you
switch between two sessions that have different ideas of what the
brightness should be. They need to listen to ConsoleKit and DTRT.

> the correct behaviour is certainly to make hal self-sufficient rather
> than relying on a side-effect caused by a feature of g-p-m that wasn't
> planned to fix this problem in the first place :)

Yeah, driver code should reinitialize the hardware on resume so it's
back at the same state when you suspend. We don't do this in the hald
backlight addons and, for the record, several of the in-kernel backlight
drivers don't do this either (try resuming from suspend-to-disk). This
doesn't mean, however, that it shouldn't be fixed; I've added an item to
doc/TODO about having a mechanism for addon's to do things in the
suspend/resume path. But as I've argue policy agents (like g-p-m) needs
to do the right thing _anyway_ so this becomes less of an issue. Also,
it's preferable for the backlight code to be a real kernel driver..

     David