Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760860AbZD1CIw (ORCPT ); Mon, 27 Apr 2009 22:08:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756325AbZD1CIm (ORCPT ); Mon, 27 Apr 2009 22:08:42 -0400 Received: from ovro.ovro.caltech.edu ([192.100.16.2]:35826 "EHLO ovro.ovro.caltech.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755506AbZD1CIm (ORCPT ); Mon, 27 Apr 2009 22:08:42 -0400 Message-ID: <49F66523.3020103@ovro.caltech.edu> Date: Mon, 27 Apr 2009 19:08:35 -0700 From: David Hawkins User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) MIME-Version: 1.0 To: Liu Dave-R63238 CC: Tabi Timur-B04825 , linuxppc-dev@ozlabs.org, Dan Williams , Zhang Wei , linux-kernel@vger.kernel.org, Ira Snyder Subject: Re: [PATCH] fsldma: use PCI Read Multiple command References: <20090424183517.GB23140@ovro.caltech.edu> <49F608B7.9080409@ovro.caltech.edu> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (ovro.ovro.caltech.edu); Mon, 27 Apr 2009 19:08:42 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1387 Lines: 34 Hi Dave, > For the DMA PCI read/line/multi-line is outbound transaction. > So according to your experiment, the 8349 PCI controller(as master) > attemp to streaming/combining the outbound transaction(treated as > prefetchable space). Yep, with the MPC8349EA configured as a PCI Target, and operating as a Bus Master, DMA transfers between two MPC8349EA targets to prefetchable memory on the slave will burst at pretty much full-speed over the PCI bus. The same goes for DMA to the host memory. However, reading from the host is slower, as the bursts get chopped up more than they do between two target boards. At some point I'll get a bunch of screen captures and put them in a document. > IIRC, the early 8349EUM has the bit[2]-SE in the POCMRn > register, and is removed now. Not sure if it does function. Hey yeah, I looked in the 8349E manual, and it is defined. I'm not sure why it would be defined there though. I can't think of why the master would want to disable streaming based on a bit setting; it should burst until the IOS says its full. Anyway, the bit is gone now, so we'll just ignore the fact it existed :) Cheers, Dave -- 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/