Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755046Ab0BOLTb (ORCPT ); Mon, 15 Feb 2010 06:19:31 -0500 Received: from sh.osrg.net ([192.16.179.4]:39370 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755325Ab0BOLT2 (ORCPT ); Mon, 15 Feb 2010 06:19:28 -0500 Date: Mon, 15 Feb 2010 20:18:41 +0900 To: mb@bu3sch.de Cc: fujita.tomonori@lab.ntt.co.jp, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net, stefano.brivio@polimi.it, Larry.Finger@lwfinger.net, akpm@linux-foundation.org Subject: Re: [PATCH -mm] ssb: open-code dma_alloc_coherent From: FUJITA Tomonori In-Reply-To: <201002151203.42805.mb@bu3sch.de> References: <20100215142111R.fujita.tomonori@lab.ntt.co.jp> <201002151203.42805.mb@bu3sch.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20100215201825M.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, 15 Feb 2010 20:18:42 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 36 On Mon, 15 Feb 2010 12:03:41 +0100 Michael Buesch wrote: > On Monday 15 February 2010 06:21:58 FUJITA Tomonori wrote: > > This patch is against -mm since it depends on the DMA API changes in > > I appreciate your efforts to remove bus-specific APIs. > However, always keep in mind that a SSB bus might be running on a system > where there's no PCI bus at all. Yup, that's why we introduced the generic device model and the generic DMA API is better. > In the past we used the generic dma_... API for DMA operations on all > SSB devices. This worked 99.9% of the time. _But_ it broke in really obscure > cases where the architecture implementations _slightly_ differed between > the generic dma and the pci variants. Yeah, I know. There are some differences between the PCI DMA API and the generic DMA API on some architectures. My patchset in -mm fixes the above problem: http://marc.info/?l=linux-kernel&m=126596737604808&w=2 http://git.kernel.org/?p=linux/kernel/git/tomo/linux-2.6-misc.git;a=blob;f=include/asm-generic/pci-dma-compat.h;h=ddfa9c5309229d171af63dcaf3872288fb4fa845;hb=refs/heads/pending The PCI DMA API simply calls the generic DMA API. And all the architectures that supports pci uses asm-generic/pci-dma-compat.h. You can use the generic DMA API with any buses. I'll remove the PCI DMA API in the long term. Thanks, -- 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/