Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263085AbUFTT1U (ORCPT ); Sun, 20 Jun 2004 15:27:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263709AbUFTT1U (ORCPT ); Sun, 20 Jun 2004 15:27:20 -0400 Received: from stat1.steeleye.com ([65.114.3.130]:19691 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S263085AbUFTT1S (ORCPT ); Sun, 20 Jun 2004 15:27:18 -0400 Subject: Re: DMA API issues From: James Bottomley To: Oliver Neukum Cc: Ian Molton , rmk+lkml@arm.linux.org.uk, david-b@pacbell.net, Linux Kernel , greg@kroah.com, tony@atomide.com, jamey.hicks@hp.com, joshua@joshuawise.com In-Reply-To: <200406202002.47025.oliver@neukum.org> References: <1087584769.2134.119.camel@mulgrave> <20040620165042.393f2756.spyro@f2s.com> <1087750024.11222.81.camel@mulgrave> <200406202002.47025.oliver@neukum.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-9) Date: 20 Jun 2004 14:27:01 -0500 Message-Id: <1087759622.10858.97.camel@mulgrave> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 774 Lines: 20 On Sun, 2004-06-20 at 13:02, Oliver Neukum wrote: > > The DMA API is about allowing devices to transact directly with memory > > behind the memory controller, it's an API that essentially allows the > > I/O controller and memory controller to communicate without CPU > > intervention. This is still possible through the hypervisor, so the > > iSeries currently fully implements the DMA API. > > Then what's the problem? If you look at the diagram, you'll see that the OHCI memory isn't behind the memory controller... 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/