Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756831AbXJYH4U (ORCPT ); Thu, 25 Oct 2007 03:56:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754068AbXJYH4K (ORCPT ); Thu, 25 Oct 2007 03:56:10 -0400 Received: from brick.kernel.dk ([87.55.233.238]:4011 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753222AbXJYH4J (ORCPT ); Thu, 25 Oct 2007 03:56:09 -0400 Date: Thu, 25 Oct 2007 09:54:25 +0200 From: Jens Axboe To: Hugh Dickins Cc: Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.24-rc1] fix sg_phys to use dma_addr_t Message-ID: <20071025075425.GD5053@kernel.dk> References: <20071024192949.346687ed@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1702 Lines: 37 On Thu, Oct 25 2007, Hugh Dickins wrote: > On Wed, 24 Oct 2007, Arjan van de Ven wrote: > > > Signed-off-by: Hugh Dickins > > > --- > > > Whether this is a complete patch, suitable for all architectures, > > > I'm not sure: it builds, boots and runs correctly on the x86_32 box > > > in question, but you'll be a lot wiser than me about using dma_addr_t > > > for everyone. (Seems a bit of a shame to include here, > > > when I think all arches already get to include it one way or another, > > > typically via asm/scatterlist.h; but I guess it's safest to repeat > > > it.) > > > > there is a problem with this... sg_phys doesn't return an actual *dma* > > address.... at least not an address you can give to the device. > > Using dma_addr_t is thus a bit misleading..... > > True. Perhaps sg_phys() should use its own sg_phys_addr_t, defined > or typedefed to be the same as dma_addr_t. But would this inline > function then be the only place in the tree which uses that type? > If so, then it'd probably be better just to let sg_phys() carry on > using dma_addr_t, but insert a comment there to make your point. > > But I'll leave it to Jens to fix up the patch appropriately: for > all I know, there might be arches on which using dma_addr_t there > actually does the wrong thing - I don't think so, but I know too > little about it. dma_addr_t would seem OK to me, given the lack of phys_addr_t. -- Jens Axboe - 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/