[Intel-gfx] BACKLIGHT property for KMS case

[Jesse Barnes]

On Tue, 18 Aug 2009 03:01:22 +0100
Matthew Garrett <mjg59 at srcf.ucam.org> wrote:

> On Mon, Aug 17, 2009 at 05:52:28PM -0700, Jesse Barnes wrote:
> 
> > The VBIOS handles it by making anything below the min brightness
> > equivalent to "lowest", which is probably fine.  Scaling would work
> > too though.  Also, the PWM write is wrong for a range of 0-255, so
> > I need some scaling anyway...
> 
> The problem with having them all at "lowest" is that you'll get a
> bunch of "low" brightness levels in the UI that all result in the
> same brightness. It's not a technical issue but it looks kind of
> ugly, so I think we need to set the zero point to the lowest value
> and reduce max_brightness accordingly.

Sure, easy enough...  Range exposed to the user will always be 0-max
but internally we'll have min-max or max-min where min can be nonzero.

-- 
Jesse Barnes, Intel Open Source Technology Center