On Mon, Jul 14, 2014 at 10:06:16PM +0530, Vinod Koul wrote:

On Fri, May 30, 2014 at 03:49:50PM -0500, Andy Gross wrote:

quoted

This patch adds support for end of transaction (EOT) and notify when done (NWD)
hardware descriptor flags.

The EOT flag requests that the peripheral assert an end of transaction interrupt
when that descriptor is complete.  It also results in special signaling protocol
that is used between the attached peripheral and the core using the DMA
controller.  Clients will specify DMA_PREP_INTERRUPT to enable this flag.

The NWD flag requests that the peripheral wait until the data has been fully
processed by the peripheral before moving on to the next descriptor.  Clients
will specify DMA_PREP_FENCE to enable this flag.

I am going to apply this, but pls send a follow up patch to add comments on the
flags and their behaviour. I think it is required!

Will do.

<snip>

quoted

 #define DESC_FLAG_EOT BIT(14)
 #define DESC_FLAG_EOB BIT(13)
+#define DESC_FLAG_NWD BIT(12)

explaining behvaiour will help..

In the followup, I'll put in a lengthy description of the INT/EOT/NWD and how
they are used in the signaling to/from the attached peripheral.


Thanks!

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