Date: Sat, 31 Jan 2009 00:27:48 +0100 (CET)
From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
To: Dan Williams <dan.j.williams@intel.com>
cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>, linux-kernel@vger.kernel.org,
       netdev@vger.kernel.org, maciej.sosnowski@intel.com,
       hskinnemoen@atmel.com, nicolas.ferre@atmel.com
Subject: Re: [PATCH 07/13] dmaengine: introduce dma_request_channel and 
 private channels
In-Reply-To: <e9c3a7c20901301513v74953d7aj8533d05cddfa510@mail.gmail.com>
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On Fri, 30 Jan 2009, Dan Williams wrote:

> On Fri, Jan 30, 2009 at 10:03 AM, Atsushi Nemoto <anemo@mba.ocn.ne.jp> wrote:
> > I'm writing a new dma driver.  My DMAC has multiple channels and only
> > one channel is capable for generic memcpy and other channels have
> > fixed role.
> >
> > Does new framework allow dma driver make only one channel public?
> 
> Yes, if the driver registers a dma_device for each channel.
> 
> > Or should I register two dma_device for DMA_MEMCPY and DMA_SLAVE?
> > Could you give me some advice?
> 
> Register multiple dma_devices, the public one with a DMA_MEMCPY, and
> the fixed role devices with DMA_PRIVATE, DMA_MEMCPY, and DMA_SLAVE
> capabilities.
> 
> DMA_PRIVATE ensures that a channel is never considered for public consumption.

Maybe just two dma-devices would suffice: one with the public memcpy 
channel, and one with the rest private slave channels?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
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