From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134Ab0C2P4h (ORCPT ); Mon, 29 Mar 2010 11:56:37 -0400 Received: from mail-gw0-f46.google.com ([74.125.83.46]:52694 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753810Ab0C2P4g convert rfc822-to-8bit (ORCPT ); Mon, 29 Mar 2010 11:56:36 -0400 MIME-Version: 1.0 In-Reply-To: <1269877373.6173.27.camel@iscandar.digidescorp.com> References: <201003172118.41559.temerkhanov@cifronik.ru> <1269877373.6173.27.camel@iscandar.digidescorp.com> From: Grant Likely Date: Mon, 29 Mar 2010 09:56:15 -0600 X-Google-Sender-Auth: 435816b9166eb18b Message-ID: Subject: Re: [PATCH] [RFC] Xilinx MPMC SDMA subsystem To: steve@digidescorp.com Cc: Sergey Temerkhanov , microblaze-uclinux@itee.uq.edu.au, Linux Kernel Mailing List , linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 29, 2010 at 9:42 AM, Steven J. Magnani wrote: > On Fri, 2010-03-26 at 17:53 -0600, Grant Likely wrote: >> I've not got time to review this patch right now, but Sergey and >> Steven, you both posted MPMC drivers on the same day; Steven on the >> microblaze list and Sergey on the powerpc list.  Can you two please >> coordinate and figure out how to mork toward a single driver that will >> meet both your needs?  I don't want to have 2 drivers (3 if you count >> the ll_temac driver) in mainline for the same hardware interface. >> > > I don't think we'll end up with a single driver. A MPMC DMA Engine > driver is useful only on "loopback" SDMA ports. Sergey's code looks like > a nice generic interface to Xilinx SDMA HW that could be used by the > xlldma and ll_temac drivers, for instance. Both of those will get > smaller, but won't go away. > > For this to be useful to me, it would need to be located somewhere more > accessible than arch/powerpc and it would need to have initialization > methods that don't depend on OF. In my build I would have platform code > that binds to the xlldma platform attachment, which would call Sergey's > SDMA code to assign it the proper resources. That should be fine. > Any objections to having Sergey's code live in drivers/dma, and putting > sdma.h out in include/linux? Might need to tweak the file/function names > some to head off namespace issues. Or is there some other strategy for > managing Xilinx-related drivers common to both Microblaze and PowerPC? I have no objections. This sounds like a good plan. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.