From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752957AbaEVTdS (ORCPT ); Thu, 22 May 2014 15:33:18 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:41834 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751669AbaEVTdQ (ORCPT ); Thu, 22 May 2014 15:33:16 -0400 Date: Thu, 22 May 2014 15:33:13 -0400 (EDT) Message-Id: <20140522.153313.958087444510569794.davem@davemloft.net> To: gang.chen.5i5j@gmail.com Cc: gerrit@erg.abdn.ac.uk, gxt@mprc.pku.edu.cn, dccp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH linux-next] net/dccp/timer.c: use 'u64' instead of 's64' to avoid compiler's warning From: David Miller In-Reply-To: <537BF116.9000900@gmail.com> References: <537BF116.9000900@gmail.com> X-Mailer: Mew version 6.6 on Emacs 24.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-7 X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Thu, 22 May 2014 12:33:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id s4MJXSh0029408 From: Chen Gang Date: Wed, 21 May 2014 08:19:34 +0800 > 'dccp_timestamp_seed' is initialized once by ktime_get_real() in > dccp_timestamping_init(). It is always less than ktime_get_real() > in dccp_timestamp(). > > Then, ktime_us_delta() in dccp_timestamp() will always return positive > number. So can use manual type cast to let compiler and do_div() know > about it to avoid warning. > > The related warning (with allmodconfig under unicore32): > > CC [M] net/dccp/timer.o > net/dccp/timer.c: In function dccp_timestamp: > net/dccp/timer.c:285: warning: comparison of distinct pointer types lacks a cast > > > Signed-off-by: Chen Gang Applied to net-next, thanks. But that type check in include/asm-generic/div64.h is bogus, it should be checking sizeof(X) == 8 rather than the type thing, it just wants to make sure that the value is 64-bit regardless of it's signedness. The arch local implementations do not do this, and that's why very few other people notice this warning. {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I