X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Fdmadevs%2Fioat.rst;h=9ac90e31089cb1e15913b5e9ad3c045077458599;hb=b54403fd08374dae243bf0a0e90488f51485154e;hp=9ee4e372a8c174d46c6f46b6340cc2c765eac869;hpb=3d4b027324be6acded76ef1b94ad862fe02189c9;p=dpdk.git

diff --git a/doc/guides/dmadevs/ioat.rst b/doc/guides/dmadevs/ioat.rst
index 9ee4e372a8..9ac90e3108 100644
--- a/doc/guides/dmadevs/ioat.rst
+++ b/doc/guides/dmadevs/ioat.rst
@@ -90,7 +90,38 @@ Performing Data Copies
 ~~~~~~~~~~~~~~~~~~~~~~~
 
 Refer to the :ref:`Enqueue / Dequeue APIs <dmadev_enqueue_dequeue>` section of the dmadev library
-documentation for details on operation enqueue and submission API usage.
+documentation for details on operation enqueue, submission and completion API usage.
 
 It is expected that, for efficiency reasons, a burst of operations will be enqueued to the
 device via multiple enqueue calls between calls to the ``rte_dma_submit()`` function.
+
+When gathering completions, ``rte_dma_completed()`` should be used, up until the point an error
+occurs with an operation. If an error was encountered, ``rte_dma_completed_status()`` must be used
+to reset the device and continue processing operations. This function will also gather the status
+of each individual operation which is filled in to the ``status`` array provided as parameter
+by the application.
+
+The status codes supported by IOAT are:
+
+* ``RTE_DMA_STATUS_SUCCESSFUL``: The operation was successful.
+* ``RTE_DMA_STATUS_INVALID_SRC_ADDR``: The operation failed due to an invalid source address.
+* ``RTE_DMA_STATUS_INVALID_DST_ADDR``: The operation failed due to an invalid destination address.
+* ``RTE_DMA_STATUS_INVALID_LENGTH``: The operation failed due to an invalid descriptor length.
+* ``RTE_DMA_STATUS_DESCRIPTOR_READ_ERROR``: The device could not read the descriptor.
+* ``RTE_DMA_STATUS_ERROR_UNKNOWN``: The operation failed due to an unspecified error.
+
+The following code shows how to retrieve the number of successfully completed
+copies within a burst and then uses ``rte_dma_completed_status()`` to check
+which operation failed and reset the device to continue processing operations:
+
+.. code-block:: C
+
+   enum rte_dma_status_code status[COMP_BURST_SZ];
+   uint16_t count, idx, status_count;
+   bool error = 0;
+
+   count = rte_dma_completed(dev_id, vchan, COMP_BURST_SZ, &idx, &error);
+
+   if (error){
+      status_count = rte_dma_completed_status(dev_id, vchan, COMP_BURST_SZ, &idx, status);
+   }