From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:56566)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1V9AfQ-0004M6-2x
	for qemu-devel@nongnu.org; Tue, 13 Aug 2013 05:13:37 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1V9AfI-0001Jw-Jg
	for qemu-devel@nongnu.org; Tue, 13 Aug 2013 05:13:28 -0400
Received: from mail-lb0-f169.google.com ([209.85.217.169]:41383)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1V9AfI-0001Jp-Dk
	for qemu-devel@nongnu.org; Tue, 13 Aug 2013 05:13:20 -0400
Received: by mail-lb0-f169.google.com with SMTP id u10so5608142lbi.14
	for <qemu-devel@nongnu.org>; Tue, 13 Aug 2013 02:13:19 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <1376383051.2737.20@driftwood>
References: <20130812164548.GE23006@n2100.arm.linux.org.uk>
	<1376383051.2737.20@driftwood>
From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 13 Aug 2013 10:12:59 +0100
Message-ID: <CAFEAcA_KJwzefBH0St2vbGd9gaWsVL9jdrGRBJU9wx2-kuo1vA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Qemu-devel] SCSI bus failures with qemu-arm in kernel 3.8+
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: Rob Landley <rob@landley.net>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, qemu-devel@nongnu.org, Paul Gortmaker <paul.gortmaker@windriver.com>, Guenter Roeck <linux@roeck-us.net>, Arnd Bergmann <arnd.bergmann@linaro.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>

On 13 August 2013 09:37, Rob Landley <rob@landley.net> wrote:
> Peter says he knows somebody who knows somebody who dug some instance of
> this hardware out of some landfill or something.

No, I personally myself had the hardware. Really.

> Me, I want to get something that works on new qemu _and_ last year's
> qemu, and that's what I got.

Note that in general hoping that current mainline kernel will
always work with ancient QEMU is a losing proposition -- it is
always possible that a kernel improvement will trigger a latent
model bug in QEMU. (To pick a random example, some while ago fixes
to how the kernel dealt with BGR and RGB pixel formats on the
versatile board broke QEMU because we weren't modelling it right;
that was just a QEMU bug for which the fix is "get a newer QEMU".)

The back-compat in the PCI code is so that the older kernels (2.6.x)
will continue to work, which is not quite the same thing.

-- PMM