From owner-svn-src-head@FreeBSD.ORG  Wed Feb 11 06:49:11 2009
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 18F771065670;
	Wed, 11 Feb 2009 06:49:11 +0000 (UTC) (envelope-from mav@FreeBSD.org)
Received: from cmail.optima.ua (cmail.optima.ua [195.248.191.121])
	by mx1.freebsd.org (Postfix) with ESMTP id 2328E8FC19;
	Wed, 11 Feb 2009 06:49:09 +0000 (UTC) (envelope-from mav@FreeBSD.org)
X-Spam-Flag: SKIP
X-Spam-Yversion: Spamooborona-2.1.0
Received: from [212.86.226.226] (account mavbsd@alkar.net HELO localhost)
	by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9)
	with ESMTPSA id 234234371; Wed, 11 Feb 2009 08:49:08 +0200
Sender: mav@FreeBSD.org
From: "Alexander Motin" <mav@FreeBSD.org>
To: "M. Warner Losh" <imp@bsdimp.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=koi8-r
Message-ID: <200902110848450000@442211619>
X-Mailer: FlexMail 4
Date: Wed, 11 Feb 2009 08:48:44 +0200
Content-Transfer-Encoding: 8bit
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
	src-committers@freebsd.org
Subject: Re: svn commit: r188464 - head/sys/kern
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 11 Feb 2009 06:49:11 -0000

>             Alexander Motin <mav@freebsd.org> writes:
> : Author: mav
> : Date: Tue Feb 10 23:22:29 2009
> : New Revision: 188464
> : URL: http://svn.freebsd.org/changeset/base/188464
> : 
> : Log:
> :   Check for device_set_devclass() errors and skip driver probe/attach if any.
> :   Attach call without devclass set crashes the system.
> :   
> :   On resume AHCI driver sometimes tries to create duplicate adX device.
> :   It is surely his own problem, but IMHO it is not a reason to crash here.
> :   Other reasons are also possible.
> : 
> : Modified:
> :   head/sys/kern/subr_bus.c
> : 
> : Modified: head/sys/kern/subr_bus.c
> : ==============================================================================
> : --- head/sys/kern/subr_bus.c	Tue Feb 10 23:17:20 2009	(r188463)
> : +++ head/sys/kern/subr_bus.c	Tue Feb 10 23:22:29 2009	(r188464)
> : @@ -1756,8 +1756,13 @@ device_probe_child(device_t dev, device_
> :  		     dl = next_matching_driver(dc, child, dl)) {
> :  			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
> :  			device_set_driver(child, dl->driver);
> : -			if (!hasclass)
> : -				device_set_devclass(child, dl->driver->name);
> : +			if (!hasclass) {
> : +				if (device_set_devclass(child, dl->driver->name)) {
> : +					PDEBUG(("Unable to set device class"));
> : +					device_set_driver(child, NULL);
> : +					continue;
> : +				}
> : +			}
> :  
> :  			/* Fetch any flags for the device before probing. */
> :  			resource_int_value(dl->driver->name, child->unit,
> 
> I'd prefer applying this patch to make it whine louder so we don't
> forget about it:

device_set_devclass() itself already complains about driver problem (but only with verbose messages). At this point the only thing we should do is not to crash. As I have said, there also can be other failure reasons except driver bugs, for example, low memory.

-- 
Alexander Motin