Re: [PATCH 1/2] drm/i915: clear up backlight inversion confusion on gen4

Daniel Vetter
2012-04-23T12:20:23Z

On Mon, Apr 23, 2012 at 10:53:31AM +0100, Chris Wilson wrote:
> On Mon, 23 Apr 2012 11:32:14 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > There's a bit in the docs for gen4 only that says whether the
> > backlight control is inverted. And both the quirk we have and
> > all bugs only concern i965gm and gm45 (and mostly Acer) afaics.
> >
> > So lets drop the quirk and use the bit instead.
> >
> > Also clean up the BLC register definitions a bit by correctly
> > grouping the CTL and CTL2 definitions together.
> >
> > This quirk was originally added in
> >
> > commit 5a15ab5b93e4a3ebcd4fa6c76cf646a45e9cf806
> > Author: Carsten Emde <C.Emde@osadl.org>
> > Date: Thu Mar 15 15:56:27 2012 +0100
> >
> > drm/i915: panel: invert brightness acer aspire 5734z
> >
> > Cc: Carsten Emde <C.Emde@osadl.org>
> > References: https://bugzilla.kernel.org/show_bug.cgi?id=31522
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=37986
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=40455
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> Oh, light dawns. That explains the polarity bit.
>
> Hmm, on PCH this bit is moved to 29 (expect for early IBX silicon)
> according to my specs.

On my specs bit29 is pipe assignement, we should set it if the panel is on
pipe B (well, it just takes the pll to do the modulation from that pipe
then).
-Daniel
--
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48