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

Geert Uytterhoeven geert at linux-m68k.org
Thu Oct 9 06:39:30 PDT 2014


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.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds



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