From owner-freebsd-usb@FreeBSD.ORG  Fri Apr  6 16:17:01 2012
Return-Path: <owner-freebsd-usb@FreeBSD.ORG>
Delivered-To: freebsd-usb@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 86833106564A
	for <freebsd-usb@freebsd.org>; Fri,  6 Apr 2012 16:17:01 +0000 (UTC)
	(envelope-from Terence_Telkamp@DELL.com)
Received: from aussmtpmrkpc120.us.dell.com (aussmtpmrkpc120.us.dell.com
	[143.166.82.159])
	by mx1.freebsd.org (Postfix) with ESMTP id 53CA48FC0C
	for <freebsd-usb@freebsd.org>; Fri,  6 Apr 2012 16:17:01 +0000 (UTC)
X-Loopcount0: from 64.238.244.148
X-IronPort-AV: E=Sophos;i="4.75,382,1330927200"; 
	d="scan'208,217";a="498474611"
Received: from mail.compellent.com ([64.238.244.148])
	by aussmtpmrkpc120.us.dell.com with ESMTP; 06 Apr 2012 11:16:54 -0500
From: Terence Telkamp <Terence_Telkamp@DELL.com>
To: "freebsd-usb@freebsd.org" <freebsd-usb@freebsd.org>
Date: Fri, 6 Apr 2012 11:16:53 -0500
Thread-Topic: Impact of changes made to umass.c at r232358
Thread-Index: Ac0UDhDs+zMpmPkJQ6y8hSkhv0Y1TA==
Message-ID: <975552A94CBC0F4DA60ED7B36C949CBA03DB0C8BA5@shandy.Beer.Town>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
acceptlanguage: en-US
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Subject: Impact of changes made to umass.c at r232358
X-BeenThere: freebsd-usb@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: FreeBSD support for USB <freebsd-usb.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-usb>
List-Post: <mailto:freebsd-usb@freebsd.org>
List-Help: <mailto:freebsd-usb-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Apr 2012 16:17:01 -0000

I am seeing a kernel panic in FreeBSD 8.1, which is reproduced after physic=
ally attaching and detaching a USB device several times.  The kernel debugg=
er shows that the panic happens in camisr where the cam_sim and its associa=
ted mutex are clearly destroyed.  sim->refcount is 0, sim->softc is 1 (UMAS=
S_GONE), and the sim->mtx is destroyed (mtx_lock =3D 6).

This looks very similar to FreeBSD PR kern/153514, which is unfortunately u=
nresolved.

http://www.freebsd.org/cgi/query-pr.cgi?pr=3D153514


Is it possible that the changes made to umass.c at r232358 might fix this i=
ssue?


Terence Telkamp
Storage Development Associate Engineer II
Dell | Compellent