From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:40793)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1ZHVsP-0002V9-Q8
	for qemu-devel@nongnu.org; Tue, 21 Jul 2015 07:38:26 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1ZHVsL-00012I-3O
	for qemu-devel@nongnu.org; Tue, 21 Jul 2015 07:38:25 -0400
Received: from mail-vn0-f47.google.com ([209.85.216.47]:36119)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1ZHVsL-00012E-0D
	for qemu-devel@nongnu.org; Tue, 21 Jul 2015 07:38:21 -0400
Received: by vnk197 with SMTP id 197so34334044vnk.3
	for <qemu-devel@nongnu.org>; Tue, 21 Jul 2015 04:38:20 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <1437416961-26348-3-git-send-email-jsnow@redhat.com>
References: <1437416961-26348-1-git-send-email-jsnow@redhat.com>
	<1437416961-26348-3-git-send-email-jsnow@redhat.com>
From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 21 Jul 2015 12:38:00 +0100
Message-ID: <CAFEAcA_7OKrZexyoAFc3Jhiib=Syf3UUKPYGNxdPmQO_wm-vMQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Qemu-devel] [PULL 2/3] ahci: Force ICC bits in PxCMD to zero
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: John Snow <jsnow@redhat.com>
Cc: Stefan Fritsch <sf@sfritsch.de>, QEMU Developers <qemu-devel@nongnu.org>

On 20 July 2015 at 19:29, John Snow <jsnow@redhat.com> wrote:
> From: Stefan Fritsch <sf@sfritsch.de>
>
> The AHCI spec requires that the HBA sets the ICC bits to zero after the
> ICC change is done. Since we don't do any ICC change, force the bits to
> zero all the time.
>
> This fixes delays with some OSs (e.g. OpenBSD) waiting for the ICC bits
> to change to 0.

This change provokes a lot of clang sanitizer warnings:

/home/petmay01/linaro/qemu-for-merges/hw/ide/ahci.c:288:49: runtime
error: left shift of 15 by 28 places cannot be represented in type
'int'

PORT_CMD_ICC_MASK is defined as

 #define PORT_CMD_ICC_MASK         (0xf << 28) /* i/f ICC state mask */

which shifts into the sign bit of a signed integer.

thanks
-- PMM