Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754875Ab3CEWDS (ORCPT ); Tue, 5 Mar 2013 17:03:18 -0500 Received: from mailout01.c08.mtsvc.net ([205.186.168.189]:51978 "EHLO mailout01.c08.mtsvc.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753281Ab3CEWDQ (ORCPT ); Tue, 5 Mar 2013 17:03:16 -0500 Message-ID: <1362520976.18799.134.camel@thor.lan> Subject: Re: [Fwd: [PATCH v2 0/4] TTY: port hangup and close fixes] From: Peter Hurley To: Jiri Slaby Cc: jhovold@gmail.com, Greg Kroah-Hartman , Alan Stern , USB list , linux-serial@vger.kernel.org, Alan Cox , LKML Date: Tue, 05 Mar 2013 17:02:56 -0500 In-Reply-To: <51366A29.2060808@suse.cz> References: <1362085054.3337.20.camel@thor.lan> <51361724.4050107@suse.cz> <1362503170.18799.33.camel@thor.lan> <51366A29.2060808@suse.cz> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.3-0pjh1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Authenticated-User: 125194 peter@hurleysoftware.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1324 Lines: 39 On Tue, 2013-03-05 at 22:56 +0100, Jiri Slaby wrote: > On 03/05/2013 06:06 PM, Peter Hurley wrote: > >>> @@ -225,15 +232,13 @@ void tty_port_hangup(struct tty_port *port) > >> spin_lock_irqsave(&port->lock, flags); > >> port->count = 0; > >> port->flags &= ~ASYNC_NORMAL_ACTIVE; > >> - if (port->tty) { > >> + if (port->tty) > >> set_bit(TTY_IO_ERROR, &port->tty->flags); > >> - tty_kref_put(port->tty); > >> - } > >> - port->tty = NULL; > >> spin_unlock_irqrestore(&port->lock, flags); > >>> + tty_port_shutdown(port, port->tty); > >> > >> What prevents port->tty to be NULL here already? > > > > Nothing. That's why it's tested in tty_port_shutdown() above. > > I know :). Sorry :) > But the question is rather don't we want to pass the real > refcounted port->tty (take a snapshot inside the lock) instead? I think that's why he moved the kref release to after the shutdown (via tty_port_set_tty()) -- but I'm tired and maybe I'm missing something here? Regards, Peter Hurley -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/