Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752272Ab0HTKQ2 (ORCPT ); Fri, 20 Aug 2010 06:16:28 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:53837 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751499Ab0HTKQ0 (ORCPT ); Fri, 20 Aug 2010 06:16:26 -0400 Date: Fri, 20 Aug 2010 11:31:25 +0100 From: Alan Cox To: Andrew Morton Cc: Alan Cox , Michal Simek , michal.simek@petalogix.com, Greg Kroah-Hartman , Ralf Baechle , Manuel Lauss , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] serial: 8250: Initialize pointer to irq_info Message-ID: <20100820113125.6d7b498f@lxorguk.ukuu.org.uk> In-Reply-To: <20100819164354.09e30dc9.akpm@linux-foundation.org> References: <1282031947-16483-1-git-send-email-monstr@monstr.eu> <20100817091720.56183993@linux.intel.com> <20100819164354.09e30dc9.akpm@linux-foundation.org> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: 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 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: 994 Lines: 34 > > Use a newer compiler - modern ones get this right. > > : static void serial_unlink_irq_chain(struct uart_8250_port *up) > : { > : struct irq_info *i; > : struct hlist_node *n; > : struct hlist_head *h; > : > : mutex_lock(&hash_mutex); > : > : h = &irq_lists[up->port.irq % NR_IRQ_HASH]; > : > : hlist_for_each(n, h) { > : i = hlist_entry(n, struct irq_info, node); > : if (i->irq == up->port.irq) > : break; > : } > : > : BUG_ON(n == NULL); > : BUG_ON(i->head == NULL); > > How can any compiler possibly determine that the hlist_for_each() is > never executed zero times? We had this argument was it two years ago ? Modern gcc is capable of at least working out it can't work it out and doesn't emit a spurious warning. -- 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/