From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753630Ab0C2UPB (ORCPT ); Mon, 29 Mar 2010 16:15:01 -0400 Received: from forward3.mail.yandex.net ([77.88.46.8]:46440 "EHLO forward3.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752192Ab0C2UO5 (ORCPT ); Mon, 29 Mar 2010 16:14:57 -0400 X-Greylist: delayed 536 seconds by postgrey-1.27 at vger.kernel.org; Mon, 29 Mar 2010 16:14:57 EDT From: Sergey Temerkhanov To: linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] [RFC] Xilinx MPMC SDMA subsystem Date: Mon, 29 Mar 2010 23:04:39 +0400 User-Agent: KMail/1.12.4 (Linux/2.6.31.12-0.2-desktop; KDE/4.3.5; x86_64; ; ) Cc: Grant Likely , steve@digidescorp.com, microblaze-uclinux@itee.uq.edu.au, Sergey Temerkhanov , Linux Kernel Mailing List References: <201003172118.41559.temerkhanov@cifronik.ru> <1269877373.6173.27.camel@iscandar.digidescorp.com> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201003292304.39657.temerkhanov@yandex.ru> X-Yandex-TimeMark: 1269893159 X-Yandex-Spam: 1 X-Yandex-Front: smtp4.mail.yandex.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 29 March 2010 19:56:15 Grant Likely wrote: > 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. Yes, it's like having IBM EMAC driver and MAL layer or something > > > > 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. Well, I'll look at my old code for the platform interface bindings. I remember it worked well on arch/ppc with my other drivers. > > > 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. Or we can put Xilinx-related headers to, i.e., include/linux/xilinx. There might be some other candidates for this. > > g. > Regards, Sergey Temerkhanov, Cifronic ZAO