Laptop Panel brightness control

[Crispin Flowerday]

Hi,

While trying to fix http://bugzilla.gnome.org/show_bug.cgi?id=340231 it
was discovered that laptops behave differently when the brightness
control buttons are used.

Specifically, my IBM x31 controls the brightness itself (so g-p-m just
needs to monitor the setting), whereas Richard Hughes's laptop (can't
remember what it was just at the moment) just uses the buttons to talk
to software which then has to control the brightness (so g-p-m needs to
talk to the hardware directly).

So, we really could do with a HAL property to differentiate the 2 cases,
how about "laptop_panel.brightness_in_hardware"?

Thoughts?

Crispin