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

Maxime Ripard
2014-08-02T19:06:15Z

On Sat, Aug 02, 2014 at 04:17:14PM +0100, Russell King - ARM Linux wrote:
> On Sat, Aug 02, 2014 at 04:49:25PM +0200, Maxime Ripard wrote:
> > In the case of the call to device_control, especially in the
> > DMA_SLAVE_CONFIG case, but that also applies to pause/resume, are the
> > changes supposed to be immediates or can they happen later?
>
> pause/resume are expected to operate synchronously on the channel.
> When asking for the channel to pause, the channel must be stopped
> before the call returns.
>
> In the case of channel configuration, that should have no effect on
> any previously queued transfer - in other words, changing the channel
> configuration only has an effect when subsequent transactions are
> prepared.

Ok, thanks!

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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