Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754782AbZGFC3W (ORCPT ); Sun, 5 Jul 2009 22:29:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753672AbZGFC3O (ORCPT ); Sun, 5 Jul 2009 22:29:14 -0400 Received: from sh.osrg.net ([192.16.179.4]:39812 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536AbZGFC3N (ORCPT ); Sun, 5 Jul 2009 22:29:13 -0400 Date: Mon, 6 Jul 2009 11:28:32 +0900 To: tom.leiming@gmail.com Cc: arnd@arndb.de, joerg.roedel@amd.com, fujita.tomonori@lab.ntt.co.jp, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH 0/3] dma-mapping:remove CONFIG_HAVE_DMA_ATTRS From: FUJITA Tomonori In-Reply-To: <20090705204418.44fc38c1@linux-lm> References: <1246674895-9610-1-git-send-email-tom.leiming@gmail.com> <200907051319.37169.arnd@arndb.de> <20090705204418.44fc38c1@linux-lm> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20090706112811A.fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Mon, 06 Jul 2009 11:28:34 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1263 Lines: 26 On Sun, 5 Jul 2009 20:44:18 +0800 Ming Lei wrote: > On Sun, 5 Jul 2009 13:19:36 +0200 > Arnd Bergmann wrote: > > > On Saturday 04 July 2009, tom.leiming@gmail.com wrote: > > > 2,Disabling CONFIG_HAVE_DMA_ATTRS may lead to a compile failure; > > > > I'm not sure I understand this point. CONFIG_HAVE_DMA_ATTRS tells > > the common code whether the architecture understands dma attributes. > > If a new arch does not define CONFIG_HAVE_DMA_ATTRS but uses > dma-mapping-common.h, it will lead to a compile failure. Yeah, architectures that use dma-mapping-common.h need to define CONFIG_HAVE_DMA_ATTRS because dma-mapping-common.h needs to handle architectures that need CONFIG_HAVE_DMA_ATTRS. Your idea doesn't sound good to me. I think that it's better to define CONFIG_HAVE_DMA_ATTRS in the consistent way; defining arch's Kconfig. Defining CONFIG_HAVE_DMA_ATTRS in two different ways and inventing another define such as ARCH_USE_DMA_MAPPING_COMMON is just confusing. -- 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/