From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753177AbaKXJKK (ORCPT <rfc822;w@1wt.eu>);
	Mon, 24 Nov 2014 04:10:10 -0500
Received: from mail-lb0-f179.google.com ([209.85.217.179]:63750 "EHLO
	mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752790AbaKXJKI (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 24 Nov 2014 04:10:08 -0500
Date: Mon, 24 Nov 2014 10:10:03 +0100
From: Johan Hovold <johan@kernel.org>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: SF Markus Elfring <elfring@users.sourceforge.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Johan Hovold <johan@kernel.org>, linux-usb@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>, kernel-janitors@vger.kernel.org
Subject: Re: USB: serial: Deletion of an unnecessary check before the
 function call "release_firmware"
Message-ID: <20141124091003.GA6875@localhost>
References: <alpine.DEB.2.10.1402251840450.7035@hadrien>
 <530CF8FF.8080600@users.sourceforge.net>
 <alpine.DEB.2.02.1402252117150.2047@localhost6.localdomain6>
 <530DD06F.4090703@users.sourceforge.net>
 <alpine.DEB.2.02.1402262129250.2221@localhost6.localdomain6>
 <5317A59D.4@users.sourceforge.net>
 <546F5831.5060404@users.sourceforge.net>
 <alpine.DEB.2.10.1411211625380.2433@hadrien>
 <546F5ED7.1000206@users.sourceforge.net>
 <alpine.DEB.2.10.1411211857590.2433@hadrien>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <alpine.DEB.2.10.1411211857590.2433@hadrien>
User-Agent: Mutt/1.5.22 (2013-10-16)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Nov 21, 2014 at 06:59:00PM +0100, Julia Lawall wrote:
> On Fri, 21 Nov 2014, SF Markus Elfring wrote:
> 
> > >> diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c
> > >> index ab1d690..3653ec1 100644
> > >> --- a/drivers/usb/serial/mxuport.c
> > >> +++ b/drivers/usb/serial/mxuport.c
> > >> @@ -1101,8 +1101,7 @@ static int mxuport_probe(struct usb_serial *serial,
> > >>  	 */
> > >>  	usb_set_serial_data(serial, (void *)id->driver_info);
> > >>  out:
> > >> -	if (fw_p)
> > >> -		release_firmware(fw_p);
> > >> +	release_firmware(fw_p);
> > >
> > > I think that the if should stay.
> >
> > I have got an other opinion.
> >
> >
> > > There were two cases on the allocation, so there should be two cases
> > > on the release.
> >
> > I find that this implementation detail does not really matter for the
> > necessity of a null pointer check directly before such a function call.
> 
> Conceptually, if it is clear 10 lines above that nothing was allocated,
> and there is a fallback to existing data (according to the comment above)
> it is strange to be releasing something.

I agree with Julia here and will not apply this one.

Thanks,
Johan