From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH] drm/i915: Avoid reading fbc registers in
 vain when fbc was never enabled.
Date: Fri, 19 Sep 2014 17:40:07 +0200
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To: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>, Rodrigo Vivi <rodrigo.vivi@intel.com>, Paulo Zanoni <paulo.r.zanoni@intel.com>
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On Thu, Sep 18, 2014 at 11:42:44AM -0700, Rodrigo Vivi wrote:
> On Thu, Sep 18, 2014 at 4:39 AM, Daniel Vetter <daniel@ffwll.ch> wrote:
> 
> > On Thu, Sep 18, 2014 at 07:28:48AM +0100, Chris Wilson wrote:
> > > On Wed, Sep 17, 2014 at 04:59:20PM -0400, Rodrigo Vivi wrote:
> > > > If it wasn't never enabled by kernel parameter or platform default
> > > > we can avoid reading registers so many times in vain
> > >
> > > Nak.
> >
> > Well I've merged this for now to reduce fbc impact.
> >
> 
> Uhm, unfortunatelly I'm afraid Chris was right.
> Paulo also nacked it. Because it just helps when it was explicitly disabled
> by setting i915.enable_fbc=0 while the default is -1.
> 
> I though about returning on <= 0, but Paulo is afraid that when enabling
> back for some platform people would forget to fix this part here and I
> agree.

Well I guess I should have read mails before pushing out a new -next ;-)
So this is now baked in. Should I revert or can we just fix up on top?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch