From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 24 May 2002 17:20:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 24 May 2002 17:20:23 -0400 Received: from 64-166-72-142.ayrnetworks.com ([64.166.72.142]:29064 "EHLO ayrnetworks.com") by vger.kernel.org with ESMTP id ; Fri, 24 May 2002 17:20:22 -0400 Date: Fri, 24 May 2002 14:18:56 -0700 From: William Jhun To: "David S. Miller" Cc: linux-kernel@vger.kernel.org Subject: Re: Possible discrepancy regarding streaming DMA mappings in DMA-mapping.txt? Message-ID: <20020524141856.M7205@ayrnetworks.com> In-Reply-To: <20020524133711.K7205@ayrnetworks.com> <20020524.132641.104219414.davem@redhat.com> <20020524135842.L7205@ayrnetworks.com> <20020524.135352.131897757.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 24, 2002 at 01:53:52PM -0700, David S. Miller wrote: > Now that we've established that, you want a new operation. > That operation is "Re-prepare DMA memory so that PCI realm > will see it". And the semantics of this would be to, on > CPUs which are no cache coherent with PCI, to flush the cache > to prevent inconsistencies between PCI and the CPU. > > The CPU cache flush is needed in both cases to/from cases. > > So do you finally understand why you must create a new interface > to accomplish what you want? Yes, that clears things up. I'll work on this. Thanks, William