[PATCH 16/18] dmaengine/amba-pl08x: Add support for sg len greater than one for slave transfers

Viresh Kumar viresh.kumar at st.com
Thu Aug 25 23:41:02 EDT 2011


On 8/23/2011 9:52 AM, Viresh Kumar wrote:
> On 8/21/2011 2:03 PM, Russell King - ARM Linux wrote:
>>>> I am not sure if i get this completely. In memcpy, we still don't support
>>>> more than one sg. We have created a new member in txd, which keeps track of
>>>> data (addresses, len).
>> Yes, but we shouldn't need to translate it into any kind of scatterlist.
>>
> 
> Ok. I way out is keeping two separate variables in txd, list for slave transfers,
> and pointer to single element for memcpy. And that looks to be even bad to me.
> Why waste memory, for second variable. Or create union of both.
> 
> One more thing, we can actually have scatter gather in memcpy too in future. This will be
> helpful then also. But surely that's something not implemented currently.
> 

Russell/Linus,

Probably this is the only issue left in this patch. (Sorry if i missed some other points)
Please suggest what should i modify here, so that Vinod can go ahead and push pending
patches too.

-- 
viresh



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