From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:52899)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <christoffer.dall@linaro.org>) id 1YmlXU-0005sd-5V
	for qemu-devel@nongnu.org; Mon, 27 Apr 2015 12:05:45 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <christoffer.dall@linaro.org>) id 1YmlXP-0006Ge-5p
	for qemu-devel@nongnu.org; Mon, 27 Apr 2015 12:05:44 -0400
Received: from mail-la0-f53.google.com ([209.85.215.53]:36463)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <christoffer.dall@linaro.org>) id 1YmlXO-0006GF-SY
	for qemu-devel@nongnu.org; Mon, 27 Apr 2015 12:05:39 -0400
Received: by lagv1 with SMTP id v1so83625488lag.3
	for <qemu-devel@nongnu.org>; Mon, 27 Apr 2015 09:05:38 -0700 (PDT)
Date: Mon, 27 Apr 2015 18:06:04 +0200
From: Christoffer Dall <christoffer.dall@linaro.org>
Message-ID: <20150427160604.GA23335@cbox>
References: <1428528060-17896-1-git-send-email-christoffer.dall@linaro.org>
	<1428528060-17896-4-git-send-email-christoffer.dall@linaro.org>
	<CAFEAcA9GLXT60dwCRnCur7A=EUhcwXrFb_2U8VGHX87R4ng4Xg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAFEAcA9GLXT60dwCRnCur7A=EUhcwXrFb_2U8VGHX87R4ng4Xg@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH 3/3] target-arm: Add the GICv2m to the virt
 board
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>, Eric Auger <eric.auger@linaro.org>

On Tue, Apr 21, 2015 at 03:47:13PM +0100, Peter Maydell wrote:

[...]

> > @@ -340,9 +357,31 @@ static void fdt_add_gic_node(VirtBoardInfo *vbi)
> >                                       2, vbi->memmap[VIRT_GIC_DIST].size,
> >                                       2, vbi->memmap[VIRT_GIC_CPU].base,
> >                                       2, vbi->memmap[VIRT_GIC_CPU].size);
> > +    qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#address-cells", 0x2);
> > +    qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#size-cells", 0x2);
> > +    qemu_fdt_setprop(vbi->fdt, "/intc", "ranges", NULL, 0);
> >
> 
> Why do we need an empty ranges attribute?
> 

Without it, Linux fails to make things work.  I suspect this is related
to specifically setting the #address-cells and #size-cells.

I forgot by now, but I think when I originally wrote this patch I traced
through the Linux code and found out that it was required somewhere.

I also think the AMD GICv2m FDT has the empty ranges property.

-Christoffer