From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=42566 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1OnXHh-0001DI-PS
	for qemu-devel@nongnu.org; Mon, 23 Aug 2010 09:42:01 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <anthony@codemonkey.ws>) id 1OnX3i-0007nx-BZ
	for qemu-devel@nongnu.org; Mon, 23 Aug 2010 09:27:31 -0400
Received: from mail-yx0-f173.google.com ([209.85.213.173]:51099)
	by eggs.gnu.org with esmtp (Exim 4.69)
	(envelope-from <anthony@codemonkey.ws>) id 1OnX3i-0007nr-7M
	for qemu-devel@nongnu.org; Mon, 23 Aug 2010 09:27:30 -0400
Received: by yxn35 with SMTP id 35so2265000yxn.4
	for <qemu-devel@nongnu.org>; Mon, 23 Aug 2010 06:27:29 -0700 (PDT)
Message-ID: <4C72773F.20405@codemonkey.ws>
Date: Mon, 23 Aug 2010 08:27:27 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
References: <20100803161914.15514.59304.stgit@localhost6.localdomain6>	<m38w41psje.fsf@blackfin.pond.sub.org>	<1282308092.3860.0.camel@x201>	<m3tymp9tgp.fsf@blackfin.pond.sub.org>	<4C6EA5C9.8080700@codemonkey.ws>	<m3vd756z38.fsf@blackfin.pond.sub.org>
	<4C6EC5AA.6050502@codemonkey.ws> <4C725AA4.2020905@redhat.com>
In-Reply-To: <4C725AA4.2020905@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: [Qemu-devel] Re: [PATCH] qdev: Reset hotplugged devices
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/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: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>, glommer@redhat.com, Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org

On 08/23/2010 06:25 AM, Paolo Bonzini wrote:
> On 08/20/2010 08:12 PM, Anthony Liguori wrote:
>> +/* Returns false to terminate walk; true to continue */
>> +typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);
>> +
>
> Since you're introducing qbus_walk_children, I suggest a different 
> interface: qdev_walkerfn should return 0 to walk children, -1 to skip 
> walking children, and anything else to terminate walk.  If anything 
> ever returns x > 0, qbus_walk_children returns that x, else 
> qbus_walk_children returns 0.  This interface is inspired by a similar 
> one in GCC and it works well.

Good suggestion.

Regards,

Anthony Liguori

> If you don't want to introduce the full complication, removing the "-1 
> to skip walking children" part would still give the same flexibility 
> WRT to the return values, which is the important part.
>
> Paolo