Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755975Ab0FNUxV (ORCPT ); Mon, 14 Jun 2010 16:53:21 -0400 Received: from poutre.nerim.net ([62.4.16.124]:55770 "EHLO poutre.nerim.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755730Ab0FNUxT (ORCPT ); Mon, 14 Jun 2010 16:53:19 -0400 Date: Mon, 14 Jun 2010 22:53:15 +0200 From: Jean Delvare To: "Justin P. Mattock" Cc: linux-kernel@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-bluetooth@vger.kernel.org, clemens@ladisch.de, debora@linux.vnet.ibm.com, dri-devel@lists.freedesktop.org, linux-i2c@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-media@vger.kernel.org Subject: Re: [PATCH 6/8]i2c:i2c_core Fix warning: variable 'dummy' set but not used Message-ID: <20100614225315.2bae9e37@hyperion.delvare> In-Reply-To: <1276547208-26569-7-git-send-email-justinmattock@gmail.com> References: <1276547208-26569-1-git-send-email-justinmattock@gmail.com> <1276547208-26569-7-git-send-email-justinmattock@gmail.com> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.14.4; i586-suse-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1881 Lines: 54 Hi Justin, On Mon, 14 Jun 2010 13:26:46 -0700, Justin P. Mattock wrote: > could be a right solution, could be wrong > here is the warning: > CC drivers/i2c/i2c-core.o > drivers/i2c/i2c-core.c: In function 'i2c_register_adapter': > drivers/i2c/i2c-core.c:757:15: warning: variable 'dummy' set but not used > > Signed-off-by: Justin P. Mattock > > --- > drivers/i2c/i2c-core.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index 1cca263..79c6c26 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -794,6 +794,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap) > mutex_lock(&core_lock); > dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, > __process_new_adapter); > + if(!dummy) > + dummy = 0; One word: scripts/checkpatch.pl In other news, the above is just plain wrong. First we force people to read the result of bus_for_each_drv() and then when they do and don't need the value, gcc complains, so we add one more layer of useless code, which developers and possibly tools will later wonder and complain about? I can easily imagine that a static code analyzer would spot the above code as being a potential bug. Let's stop this madness now please. Either __must_check goes away from bus_for_each_drv() and from every other function which raises this problem, or we must disable that new type of warning gcc 4.6.0 generates. Depends which warnings we value more, as we can't sanely have both. > mutex_unlock(&core_lock); > > return 0; -- Jean Delvare -- 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/