From owner-freebsd-usb@FreeBSD.ORG  Mon Nov  1 14:38:38 2010
Return-Path: <owner-freebsd-usb@FreeBSD.ORG>
Delivered-To: freebsd-usb@freebsd.org
Received: by hub.freebsd.org (Postfix, from userid 1233)
	id C5CAC1065698; Mon,  1 Nov 2010 14:38:38 +0000 (UTC)
Date: Mon, 1 Nov 2010 14:38:38 +0000
From: Alexander Best <arundel@freebsd.org>
To: Alexander Motin <mav@FreeBSD.org>
Message-ID: <20101101143838.GA64120@freebsd.org>
References: <20101020153040.GA3184@freebsd.org>
	<201010201955.56816.hselasky@c2i.net>
	<4CC529CF.8000304@FreeBSD.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4CC529CF.8000304@FreeBSD.org>
Cc: freebsd-current@freebsd.org, freebsd-usb@freebsd.org
Subject: Re: serious issue caused by usb device,
	stalling almost all operations
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: Mon, 01 Nov 2010 14:38:38 -0000

On Mon Oct 25 10, Alexander Motin wrote:
> Hans Petter Selasky wrote:
> > On Wednesday 20 October 2010 17:30:40 Alexander Best wrote:
> >> hi there,
> >>
> >> i'm running HEAD (r213495; amd64). i stumbled upon this severe problem:
> >>
> >> after attaching my mobile phone, it simply resets without doing mount or
> >> anything. however after letting the device come up again it won't show up
> >> in the console. after detaching it the usb subsystem seemed to have
> >> completely crashed. but that's not all. the following programs now simply
> >> hang without producing any output C-C won't do anything:
> >>
> >> - dmesg
> >> - top
> >> - ps
> >> - killall
> >> - camcontrol devlist
> >> - usbconfig
> > 
> > That's most likely because USB's umass driver is waiting for cam to drain. 
> > Possibly some refcounting is not correct. I suspect this is not a USB problem. 
> > Try to enter into the debugger, and look for backtrace for function stuck in 
> > umass_detach.

i set debug.kdb.panic=1, but didn't work, because writing the core dump stalled
and watchdog came up.

any advice?

cheers.
alex

> 
> It is a bit suspicious that problem happens only when device dies during
> request. Are you sure that running command was properly aborted when
> device got detached? Every running command has own set of references,
> denying detach.
> 
> -- 
> Alexander Motin

-- 
a13x