From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jesse Barnes <jbarnes@virtuousgeek.org>
Subject: Re: [PATCH 4/6] drm/i915: don't memset the fb buffer if
 preallocated
Date: Mon, 16 Dec 2013 16:17:07 -0800
Message-ID: <20131216161707.16f05eca@jbarnes-desktop>
References: <1386880917-2951-1-git-send-email-jbarnes@virtuousgeek.org>
	<1386880917-2951-4-git-send-email-jbarnes@virtuousgeek.org>
	<20131214112849.GL9804@phenom.ffwll.local>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <intel-gfx-bounces@lists.freedesktop.org>
Received: from alt-proxy13.mail.unifiedlayer.com
	(alt-proxy13.mail.unifiedlayer.com [67.222.34.81])
	by gabe.freedesktop.org (Postfix) with SMTP id 21A5AFA332
	for <intel-gfx@lists.freedesktop.org>;
	Mon, 16 Dec 2013 16:15:21 -0800 (PST)
In-Reply-To: <20131214112849.GL9804@phenom.ffwll.local>
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@lists.freedesktop.org
Errors-To: intel-gfx-bounces@lists.freedesktop.org
To: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
List-Id: intel-gfx@lists.freedesktop.org

On Sat, 14 Dec 2013 12:28:49 +0100
Daniel Vetter <daniel@ffwll.ch> wrote:

> On Thu, Dec 12, 2013 at 12:41:55PM -0800, Jesse Barnes wrote:
> > We want to preserve the BIOS/bootloader contents for later.
> > 
> > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> > ---
> >  drivers/gpu/drm/i915/intel_fbdev.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> > index db75f22..53675d2 100644
> > --- a/drivers/gpu/drm/i915/intel_fbdev.c
> > +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> > @@ -132,6 +132,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
> >  	struct drm_framebuffer *fb;
> >  	struct drm_i915_gem_object *obj;
> >  	int size, ret;
> > +	bool prealloc = false;
> >  
> >  	mutex_lock(&dev->struct_mutex);
> >  
> > @@ -142,6 +143,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
> >  			goto out_unlock;
> >  	} else {
> >  		DRM_DEBUG_KMS("re-using BIOS fb\n");
> > +		prealloc = true;
> >  		sizes->fb_width = intel_fb->base.width;
> >  		sizes->fb_height = intel_fb->base.height;
> >  	}
> > @@ -203,7 +205,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
> >  	 * If the object is stolen however, it will be full of whatever
> >  	 * garbage was left in there.
> >  	 */
> > -	if (ifbdev->fb->obj->stolen)
> > +	if (ifbdev->fb->obj->stolen && !prealloc)
> >  		memset_io(info->screen_base, 0, info->screen_size);
> 
> Shouldn't we just move this into intelfb_alloc? Now that allocating our
> own fb isn't the only way any more to get at one this code + comment above
> looks a bit misplaced.

We can't since we haven't ioremapped the buffer and such until after
the alloc or reuse.  It's a little awkward, I agree, but we need more
refactoring on the fbdev code to make it look nice.

-- 
Jesse Barnes, Intel Open Source Technology Center