[PATCH] DMA: extend documentation to provide more API details

[vinod.koul@intel.com (Vinod Koul)]

On Mon, Oct 07, 2013 at 05:28:37PM +0200, Guennadi Liakhovetski wrote:
> > > > > > No, not something in the middle. I was thinking about
> > > > > > 
> > > > > > (1) cookie 1-3 are submitted
> > > > > > (2) cookie 1 succeeds
> > > > > > (3) a DMA error occurs, cookies 2-3 are discarded
> > > > discarded using terminate_all right?
> > > 
> > > No, by the dmaengine driver as a part of the error processing.
> > And how will that be done...?
> 
> Sorry, I meant - DMA descriptors with cookies #2 and #3 will be cancelled 
> and recycled by the dmaengine driver. That's what you have to do, when 
> processing DMA error IRQ.
well the term cancel means someone went ahead and requested abort/terminate of a
transaction...

As we discussed in other mail on this thread the most common occurrence will be
timeout on client side and client cant cancel selectively.

For dma driver detection error, which is quite rare in slave usages, if people
think its common for them we cna indicate this thru status in callback. Then
client will know and doesnt need to query.

Recycling cookie has a large space so i dont think we will get confused
with a recycled one

--
~Vinod