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Subject: Re: [PATCH] dmaengine/dw_dmac: Add support for device_prep_dma_sg
From: Vinod Koul <vinod.koul@intel.com>
To: Pratyush Anand <pratyush.anand@st.com>
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Date: Mon, 02 Jan 2012 16:55:35 +0530
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On Mon, 2012-01-02 at 16:50 +0530, Pratyush Anand wrote:
> On 12/23/2011 9:28 PM, Vinod Koul wrote:
> > On Tue, 2011-12-13 at 14:17 +0530, Pratyush Anand wrote:
> >> Memory to memory copy with scatter gather option has been implemented in
> >> this patch. Driver can manage even if number of nodes in src and dst
> >> list is different.
> > The logic looks okay, but it would be great if we could split this
> > prepare here.
> > Possibly later when we have multiple such cases we can create templates
> > for parsing the non linear sg list and create linear lists from it.
> >
> 
> Ok. So you suggest to have one patch with a function to align sglist
> w.r.t length, and to implement this dwc_prep_dma_sg with aligned list only.
IMO that would be a much better approach
> 
> Caller of dwc_prep_dma_sg function will also call something like
> align_sg_list(unaligned_dsgl, unaligned ssgl, aligned dsgl,aligned ssgl);
and this one can be common code in dmaengine

> dwc_prep_dma_sg(chan, aligned dsgl, dnents, aligned ssgl, snents, flag);
> 
> Is that what you suggest? will do that.
> 
> It would be helpful if we can also conclude following discussion.
> https://lkml.org/lkml/2011/12/20/95
> I am waiting for your reply.
Missed that, will check it now


-- 
~Vinod