[PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API

Nicolas Ferre nicolas.ferre at atmel.com
Thu Oct 9 07:04:02 PDT 2014


On 09/10/2014 15:39, Geert Uytterhoeven :
> On Tue, Oct 7, 2014 at 4:52 PM, Maxime Ripard
> <maxime.ripard at free-electrons.com> wrote:
>>>>> +These various types will also affect how the source and destination
>>>>> +addresses change over time, as DMA_SLAVE transfers will usually have
>>>>> +one of the addresses that will increment, while the other will not,
>>>>> +DMA_CYCLIC will have one address that will loop, while the other, will
>>>>
>>>> s/the other,/the other/
>>>>
>>>>> +not change, etc.
>>>
>>> This is a little bit vague in my opinion. And usually, it is pretty
>>> implementation specific.
>>
>> Which is why we can't really be more precise. If you have any other
>> wording coming to your mind, I'm all for it :)
> 
> Perhaps:
> 
> Addresses pointing to RAM are typically incremented (or decremented) after
> each transfer. In case of a ring buffer, they may loop (DMA_CYCLIC).
> Addresses pointing to a device's register (e.g. a FIFO) are typically fixed.

+1 ;-)

Bye,
-- 
Nicolas Ferre



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