Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755918Ab0BDDen (ORCPT ); Wed, 3 Feb 2010 22:34:43 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52098 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751352Ab0BDDem (ORCPT ); Wed, 3 Feb 2010 22:34:42 -0500 Subject: Re: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg API description From: James Bottomley To: FUJITA Tomonori Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, akpm@linux-foundation.org In-Reply-To: <20100204123056Q.fujita.tomonori@lab.ntt.co.jp> References: <1265253206-17744-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> <20100203.192123.112190123.davem@davemloft.net> <20100204123056Q.fujita.tomonori@lab.ntt.co.jp> Content-Type: text/plain; charset="UTF-8" Date: Wed, 03 Feb 2010 21:34:35 -0600 Message-Id: <1265254475.2873.1716.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3163 Lines: 86 On Thu, 2010-02-04 at 12:31 +0900, FUJITA Tomonori wrote: > On Wed, 03 Feb 2010 19:21:23 -0800 (PST) > David Miller wrote: > > > 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 :-) > > Oops. > > > > > 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 > > Thanks, > > I found other two typos in the commit log so here's the update. > > = > From: FUJITA Tomonori > Subject: [PATCH -mm 1/4] DMA-API.txt: add dma_sync_single/sg API description > > This adds the description of the following eight function: > > dma_sync_single_for_cpu > pci_dma_sync_single_for_cpu > 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 API 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't > 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 > Cc: James Bottomley For what it's worth, you can add my acked by to both patches too. James -- 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/