From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 09/16] drm/i915: Store current watermark
 state in dev_priv->wm
Date: Tue, 15 Oct 2013 10:24:33 +0200
Message-ID: <20131015082433.GA4830@phenom.ffwll.local>
References: <1381335490-4906-1-git-send-email-ville.syrjala@linux.intel.com>
	<1381335490-4906-10-git-send-email-ville.syrjala@linux.intel.com>
	<CA+gsUGSu5DwGX+bnZSnTC2ygYSsqef8FOn49DHEAAEvh59Ti7g@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org>
Received: from mail-ea0-f171.google.com (mail-ea0-f171.google.com
	[209.85.215.171])
	by gabe.freedesktop.org (Postfix) with ESMTP id C692FE6A1B
	for <intel-gfx@lists.freedesktop.org>;
	Tue, 15 Oct 2013 01:24:21 -0700 (PDT)
Received: by mail-ea0-f171.google.com with SMTP id n15so3899865ead.16
	for <intel-gfx@lists.freedesktop.org>;
	Tue, 15 Oct 2013 01:24:19 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <CA+gsUGSu5DwGX+bnZSnTC2ygYSsqef8FOn49DHEAAEvh59Ti7g@mail.gmail.com>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/intel-gfx>
List-Post: <mailto:intel-gfx@lists.freedesktop.org>
List-Help: <mailto:intel-gfx-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/intel-gfx>,
	<mailto:intel-gfx-request@lists.freedesktop.org?subject=subscribe>
Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org
Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org
To: Paulo Zanoni <przanoni@gmail.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
List-Id: intel-gfx@lists.freedesktop.org

On Fri, Oct 11, 2013 at 11:21:04AM -0300, Paulo Zanoni wrote:
> 2013/10/9  <ville.syrjala@linux.intel.com>:

[snip]

> > +       previous.enable_fbc_wm = !(I915_READ(DISP_ARB_CTL) & DISP_FBC_WM_DIS);
> > +
> > +       if (memcmp(results, &previous, sizeof(*results)) == 0)
> 
> This may cause problems since we're also comparing the structure
> paddings. It seems "results" is already zero-initialized, so if you
> also zero-initialize "previous" we'll probably be fine with the
> memcmp(). But my fear is that future code changes will break this, so
> if you stick with the new memcmp please add a comment remembering us
> that we rely on zero-initializing stuff. Or maybe keep the
> old-big-ugly code.

I've added a comment about this and then smashed your presumed r-b onto
the patch. Please scream if the patch as merged isn't good enough.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch