From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH v5 1/3] ARM: add CPPI 4.1 DMA support Date: Mon, 03 Jan 2011 20:07:18 +0300 Message-ID: <4D220246.5020303@mvista.com> References: <201005152214.53993.sshtylyov@ru.mvista.com> <4D21F3F2.6090302@mvista.com> <20110103163447.GB2911@n2100.arm.linux.org.uk> <19F8576C6E063C45BE387C64729E739404BD3F2C4D@dbde02.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f46.google.com ([209.85.215.46]:43132 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198Ab1ACRIY (ORCPT ); Mon, 3 Jan 2011 12:08:24 -0500 Received: by ewy5 with SMTP id 5so6134582ewy.19 for ; Mon, 03 Jan 2011 09:08:23 -0800 (PST) In-Reply-To: <19F8576C6E063C45BE387C64729E739404BD3F2C4D@dbde02.ent.ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Gupta, Ajay Kumar" Cc: Russell King - ARM Linux , "linux-omap@vger.kernel.org" , "davinci-linux-open-source@linux.davincidsp.com" , "linux-arm-kernel@lists.infradead.org" , "Balbi, Felipe" Hello. On 03-01-2011 20:01, Gupta, Ajay Kumar wrote: >>>> Add support for Texas Instuments Communication Port Programming Interface 4.1 >>>> (CPPI 4.1) used on OMAP-L1x/DA8xx and AM35x. >>>> At this moment, only the DMA controller and queue manager are supported. >>>> Support for the buffer manager is lacking but these chips don't have it anyway. >>>> Signed-off-by: Sergei Shtylyov >>>> Signed-off-by: Sekhar Nori >>> Russell, you have recently discarded this patch from your patch >>> system. Can we know the reason? >> It was recently discussed with TI, and various people raised concerns >> about it. I don't remember the exact details, and I wish they'd raise >> them with the patch author directly. It may have been that it's >> inventing its own API rather than using something like the DMA engine >> API. >> Adding linux-omap to try to get a response there. > Sergei, > This issue was discussed recently at TI and proposal was to place it to > drivers/dma folder. Note that I have neither time nor inclination to do this work (not do I think it's even feasible), so it will have to fall on TI's shoulders... > Moreover, even Felipe also seems to move other musb > DMAs (Inventra, CPPI3.0, TUSB) to drivers/dma. Frankly speaking, I doubt that drivers/dma/ will have place for the purely MUSB specific DMA engines such as the named ones (there's no TUSB DMA BTW -- it uses OMAP DMA). > Regards, > Ajay WBR, Sergei