Bug#448467: [ltp] Re: Bug#448467: xserver-xorg-video-intel: Thinkpad brightness keys don't work

[Jesse Barnes]

On Wednesday, February 06, 2008 12:26 pm Brice Goglin wrote:
> On Fri, Dec 28, 2007 at 03:42:09PM -0200, Henrique de Moraes Holschuh wrote:
> > On Thu, 27 Dec 2007, Jesse Barnes wrote:
> > > That's good, but there has to be a list somewhere since the kernel
> > > backlight interface was so poorly designed.  I don't care if it's in
> > > the driver with an override list in xorg.conf or what, but it has to be
> > > somewhere.
> >
> > As long as one can override it with a *list* (which must include the
> > empty list to disable the feature) in xorg.conf, there is not a problem
> > to have a hardcoded default.
>
> Thanks a lot for discussing this, guys.
>
> Unfortunately, since Marcus still had problems with 2.6.24-rc4 and a
> recent snapshot of thinkpad-acpi, what do we have to wait for before
> this could work?
>
> Is anybody actually implementing something to handle the above list
> of backlight devices?

Sounds like Marcus' config will use the ACPI /sys/class/backlight interface by 
default.  I think this is a good thing, since it's the preferred method on 
thinkpads.  However, existing ACPI video drivers don't provide a nice, 
sequential set of backlight values, so it's easy to get "stuck" at a given 
backlight level if you just try to use the up/down controls.  See the lkml 
discussion with the subject "[PATCH] Rationalise ACPI backlight 
implementation" for details on that, it may be that the patch in that thread 
will work for Marcus.

Jesse