From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-gw0-f51.google.com (mail-gw0-f51.google.com [74.125.83.51]) by ozlabs.org (Postfix) with ESMTP id 2F561B7CBB for ; Tue, 30 Mar 2010 02:56:37 +1100 (EST) Received: by gwb15 with SMTP id 15so800165gwb.38 for ; Mon, 29 Mar 2010 08:56:35 -0700 (PDT) MIME-Version: 1.0 Sender: glikely@secretlab.ca 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 Message-ID: Subject: Re: [PATCH] [RFC] Xilinx MPMC SDMA subsystem To: steve@digidescorp.com Content-Type: text/plain; charset=ISO-8859-1 Cc: microblaze-uclinux@itee.uq.edu.au, Sergey Temerkhanov , linuxppc-dev@lists.ozlabs.org, Linux Kernel Mailing List List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. =A0Can you two please >> coordinate and figure out how to mork toward a single driver that will >> meet both your needs? =A0I 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. --=20 Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.