From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH v7 01/10] ARM: davinci: move private EDMA API to arm/common Date: Sat, 02 Feb 2013 04:13:57 +0400 Message-ID: <510C5A45.5050802@mvista.com> References: <1359742975-10421-1-git-send-email-mporter@ti.com> <1359742975-10421-2-git-send-email-mporter@ti.com> <5022f635a527470dbd0be932063e9cd2@DFLE72.ent.ti.com> <20130201184915.GP2244@beef> <510C1D0E.6030401@mvista.com> <20130201185820.GE29898@arwen.pp.htv.fi> <510C2A47.1090607@mvista.com> <20130201205600.GA31762@arwen.pp.htv.fi> <20130201213003.GW2637@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-lb0-f180.google.com ([209.85.217.180]:59058 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756243Ab3BBAOS (ORCPT ); Fri, 1 Feb 2013 19:14:18 -0500 Received: by mail-lb0-f180.google.com with SMTP id q12so5031297lbc.39 for ; Fri, 01 Feb 2013 16:14:16 -0800 (PST) In-Reply-To: <20130201213003.GW2637@n2100.arm.linux.org.uk> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Russell King - ARM Linux Cc: Felipe Balbi , Matt Porter , Linux DaVinci Kernel List , Chris Ball , "Cousson, Benoit" , Arnd Bergmann , Linux Documentation List , Tony Lindgren , Devicetree Discuss , Mark Brown , Linux MMC List , Linux Kernel Mailing List , Rob Herring , Grant Likely , Vinod Koul , Rob Landley , Dan Williams , Linux SPI Devel List , Linux OMAP List , Linux ARM Kernel List Hello. On 02-02-2013 1:30, Russell King - ARM Linux wrote: >> On Fri, Feb 01, 2013 at 11:49:11PM +0300, Sergei Shtylyov wrote: >>>> good point, do you wanna send some patches ? >>> I have already sent them countless times and even stuck CPPI 4.1 support (in >>> arch/arm/common/cppi41.c) in Russell's patch system. TI requested to remove the >>> patch. :-( >> sticking into arch/arm/common/ wasn't a nice move. But then again, so >> wasn't asking for the patch to be removed :-s > Err, patches don't get removed, they get moved to 'discarded'. >>>> I guess to make the MUSB side simpler we would need musb-dma-engine glue >>>> to map dmaengine to the private MUSB API. Then we would have some >>>> starting point to also move inventra (and anybody else) to dmaengine >>>> API. >>> Why? Inventra is a dedicated device's private DMA controller, why make >>> universal DMA driver for it? >> because it doesn't make sense to support multiple DMA APIs. We can check >> from MUSB's registers if it was configured with Inventra DMA support and >> based on that we can register MUSB's own DMA Engine to dmaengine API. > Hang on. This is one of the DMA implementations which is closely > coupled with the USB and only the USB? If it is... > I thought this had been discussed _extensively_ before. I thought the > resolution on it was: > 1. It would not use the DMA engine API. > 2. It would not live in arch/arm. > 3. It would be placed nearby the USB driver it's associated with. Note that all this doesn't apply to CPPI 4.1 controller (as contrasted to CPPI 3.0 support in MUSB aand EMAC drivers) -- it's shared by design. Just the implementations that are in tree have it as MUSB's sub-block, serving only MUSB. WBR, Sergei