From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-path: Received: from mail-pf0-f194.google.com ([209.85.192.194]:43030 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752633AbdKCQPW (ORCPT ); Fri, 3 Nov 2017 12:15:22 -0400 Date: Fri, 3 Nov 2017 09:15:20 -0700 From: Guenter Roeck To: Joe Perches Cc: Wim Van Sebroeck , "Gustavo A. R. Silva" , linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] watchdog: pcwd_pci: mark expected switch fall-through Message-ID: <20171103161520.GC21990@roeck-us.net> References: <20171103144915.GA6243@embeddedor.com> <20171103150423.GA10138@infomag.iguana.be> <20171103155426.GA21990@roeck-us.net> <1509724953.15520.26.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1509724953.15520.26.camel@perches.com> Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org On Fri, Nov 03, 2017 at 09:02:33AM -0700, Joe Perches wrote: > On Fri, 2017-11-03 at 08:54 -0700, Guenter Roeck wrote: > > On Fri, Nov 03, 2017 at 04:04:23PM +0100, Wim Van Sebroeck wrote: > > > Hi Gustavo, > > > > > > > In preparation to enabling -Wimplicit-fallthrough, mark switch cases > > > > where we are expecting to fall through. > > > > > > > > Notice that in this particular case I replaced "Fall" with a proper > > > > "fall through" comment, which is what GCC is expecting to find. > > > > > > > > Signed-off-by: Gustavo A. R. Silva > > > > --- > > > > drivers/watchdog/pcwd_pci.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/watchdog/pcwd_pci.c b/drivers/watchdog/pcwd_pci.c > > > > index c0d07ee..c882252 100644 > > > > --- a/drivers/watchdog/pcwd_pci.c > > > > +++ b/drivers/watchdog/pcwd_pci.c > > > > @@ -545,7 +545,7 @@ static long pcipcwd_ioctl(struct file *file, unsigned int cmd, > > > > return -EINVAL; > > > > > > > > pcipcwd_keepalive(); > > > > - /* Fall */ > > > > + /* fall through */ > > > > } > > > > > > > > case WDIOC_GETTIMEOUT: > > > > -- > > > > 2.7.4 > > > > > > > > > > Shouldn't the /* fall through */ come after the } ? > > > > > > > Good question. This is an unconditional code block needed to declare > > a local variable within the case statement. What is correct in that > > situation ? > > I think it'd be clearer to avoid the trivial fallthrough > optimization/complexity and just directly use > > return put_user(new_heartbeat, p); > > as heartbeat and new_heartbeat are now the same value here. > I don't think it really matters. What would matter would be for someone to convert he driver to use the watchdog subsystem. Guenter