Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756254Ab0BDDVO (ORCPT ); Wed, 3 Feb 2010 22:21:14 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41359 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754948Ab0BDDVK (ORCPT ); Wed, 3 Feb 2010 22:21:10 -0500 Date: Wed, 03 Feb 2010 19:21:23 -0800 (PST) Message-Id: <20100203.192123.112190123.davem@davemloft.net> To: fujita.tomonori@lab.ntt.co.jp Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, James.Bottomley@suse.de Subject: Re: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg API description From: David Miller In-Reply-To: <1265253206-17744-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> References: <1265253206-17744-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) 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: 1472 Lines: 38 From: FUJITA Tomonori Date: Thu, 4 Feb 2010 12:13:22 +0900 > This adds the description of the following eight function: > > dma_sync_single_for_cpu > pci_dma_sync_single_for_cpuvoid ^^^^ That "void" is probably some cut and paste error :-) > dma_sync_single_for_device > pci_dma_sync_single_for_device > dma_sync_sg_for_cpu > pci_dma_sync_sg_for_cpu > dma_sync_sg_for_device > pci_dma_sync_sg_for_device > > It was unclear that the API permits a partial sync (some network > drivers already do though). I made it clear that the sync_single API > can do a partial sync but the sync_sg API can't. > > We could do a partial sync with the sync_sg too, however, it's > difficult for driver writers to correctly use the sync_sg API for a > partial sync since the scatterlists passed in to the mapping API can > be modified. It's unlikely that driver writers want to do a partial > sync with the sync_sg API (because the sync_sg API are usually used > for block drivers). So I think that it's better to forbid a partial > sync with the sync_sg API. > > Signed-off-by: FUJITA Tomonori Acked-by: David S. Miller -- 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/