Re: [PATCHv4] DMAEngine: Define interleaved transfer request api

[Barry Song]

2011/10/1 Jassi Brar <jaswinder.singh@xxxxxxxxxx>:
> On 30 September 2011 12:13, Barry Song <21cnbao@xxxxxxxxx> wrote:
>>
>> i support we can update dma_data_direction to: Â MEM_TO_MEM,
>> MEM_TO_DEV, ÂDEV_TO_MEM, DEV_TO_DEV.
>>
> So basically you are suggesting to replace 'enum dma_data_direction'
> with 'enum xfer_direction'
> I am not sure about that. I think they represent different things and
> hence should be separate.
> dma_data_direction tells the mapping of a buffer while the other
> tells if the src and dst are memory or a device's FIFO.
>
you are kind of right now. now people use dma_data_direction to do
mapping for dma buffer. even with all 4 direction, people still use
the old two direction to do mapping. For example, it can't use
MEM_TO_MEM to map, it still need to know whether the memory is source
or dest.

i just don't like to the two old macro names. it seems i get a ticket
flying from New York to Beijing, but actually, we fly to Mexico...
so by the moment, dma_data_direction seems just to mean how to do map,
but xfer_direction is the real transfer direction.

How could we have two macro names: SRC_MEM, DEST_MEM for mapping. or just add:
dma_map_single_src
dma_map_single_dst
...
Thanks
barry
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