From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753559AbZKTXvw (ORCPT ); Fri, 20 Nov 2009 18:51:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753160AbZKTXvv (ORCPT ); Fri, 20 Nov 2009 18:51:51 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:36561 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752476AbZKTXvu (ORCPT ); Fri, 20 Nov 2009 18:51:50 -0500 Date: Fri, 20 Nov 2009 15:51:52 -0800 From: Andrew Morton To: Greg KH Cc: Jiri Slaby , linux-kernel@vger.kernel.org, Alan Cox , Greg Kroah-Hartman Subject: Re: [PATCH 1/1] Char: cyclades, fix compiler warning Message-Id: <20091120155152.1fe79030.akpm@linux-foundation.org> In-Reply-To: <20091120174328.GB14888@kroah.com> References: <20091114080505.7715b022.akpm@linux-foundation.org> <1258546702-29591-1-git-send-email-jslaby@novell.com> <20091120174328.GB14888@kroah.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; x86_64-pc-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 On Fri, 20 Nov 2009 09:43:28 -0800 Greg KH wrote: > > diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c > > index a188c05..e026f24 100644 > > --- a/drivers/char/cyclades.c > > +++ b/drivers/char/cyclades.c > > @@ -595,14 +595,8 @@ static void cyy_chip_tx(struct cyclades_card *cinfo, unsigned int chip, > > channel = save_xir & CyIRChannel; > > save_car = readb(base_addr + (CyCAR << index)); > > cy_writeb(base_addr + (CyCAR << index), save_xir); > > - info = &cinfo->ports[channel + chip * 4]; > > > > - /* validate the port# (as configured and open) */ > > - if (channel + chip * 4 >= cinfo->nports) { > > - cy_writeb(base_addr + (CySRER << index), > > - readb(base_addr + (CySRER << index)) & ~CyTxRdy); > > - goto end; > > - } > > + info = &cinfo->ports[channel + chip * 4]; > > Wierd, but this doesn't apply at all to my or Linus's tree. Are there > some other cyclades patch floating around out there that is needed here > before this one? Jiri's patch is based on top of my initial half-assed fix. Against mainline: From: Jiri Slaby With gcc 4.0.2: drivers/char/cyclades.c: In function 'cyy_interrupt': drivers/char/cyclades.c:581: warning: 'info' may be used uninitialized in this function introduced by : commit 3aeea5b92210083c7cffd4f08a0bb141d3f2d574 : Author: Jiri Slaby : AuthorDate: Sat Sep 19 13:13:16 2009 -0700 : Commit: Live-CD User : CommitDate: Sat Sep 19 13:13:16 2009 -0700 : : cyclades: introduce cyy_readb/writeb In fact the true branch which uses uninitialized 'info' can never happen because chip is always less than ->nchips and channel is always less than 4 which we alloc. So behave similar to rx handling and remove the test completely. I wonder why gcc 4.4.1 doesn't spit a word. Reported-by: Andrew Morton Cc: Alan Cox Cc: Greg Kroah-Hartman Signed-off-by: Jiri Slaby Signed-off-by: Andrew Morton --- drivers/char/cyclades.c | 6 ------ 1 file changed, 6 deletions(-) diff -puN drivers/char/cyclades.c~char-cyclades-fix-compiler-warning drivers/char/cyclades.c --- a/drivers/char/cyclades.c~char-cyclades-fix-compiler-warning +++ a/drivers/char/cyclades.c @@ -598,12 +598,6 @@ static void cyy_chip_tx(struct cyclades_ save_car = readb(base_addr + (CyCAR << index)); cy_writeb(base_addr + (CyCAR << index), save_xir); - /* validate the port# (as configured and open) */ - if (channel + chip * 4 >= cinfo->nports) { - cy_writeb(base_addr + (CySRER << index), - readb(base_addr + (CySRER << index)) & ~CyTxRdy); - goto end; - } info = &cinfo->ports[channel + chip * 4]; tty = tty_port_tty_get(&info->port); if (tty == NULL) { _