[PATCH] [Quantal](pre-stable)drm/i915/lvds: ditch ->prepare special case

[Andy Whitcroft]

On Thu, Jan 24, 2013 at 01:23:11PM +0000, Colin Ian King wrote:
> On 24/01/13 08:46, Haitao Zhang wrote:
> > From 3273adbb6123abdda68695b663b1c4cc97e00fe9 Mon Sep 17 00:00:00 2001
> >From: Daniel Vetter <daniel.vetter at ffwll.ch>
> >Date: Wed, 11 Jul 2012 16:27:52 +0200
> >Subject: [PATCH] [Quantal](pre-stable)drm/i915/lvds: ditch ->prepare special
> >  case

It should be noted that this is not (pre-stable).  It is upstream and in
Raring already.

> >-	/*
> >-	 * Prior to Ironlake, we must disable the pipe if we want to adjust
> >-	 * the panel fitter. However at all other times we can just reset
> >-	 * the registers regardless.
> >-	 */
> >-	if (!HAS_PCH_SPLIT(encoder->dev) && intel_lvds->pfit_dirty)
> >-		intel_lvds_disable(intel_lvds);
> >+	intel_lvds_disable(intel_lvds);

It think this says that behaviour prior to ironlake is unchanged with this
removal.  But I do think we need to confirm an older system with this, and
several affected ones to confirm there is no regression potential on this.

>From the description in the bug, this is ultimatly needed for
linux-lts-quantal in precise.  It fixes a flash of white during resume
from suspend, so any testing needs to test that part as well as have
visual confirmation during boot.  I suspect we may be introducing a
flash to black in some cases.

-apw