[dpdk-dev] [PATCH] pmd_ring: return new port id on ethdev creation

[Bruce Richardson]

The rte_eth_from_rings API allowed the creation of an ethdev port at
runtime using rte_rings as the underlying storage. However, the return
value from this function was either 0 or -1, and these values were never
actually documented in the API documentation. Unfortunately, the programmers
guide doc examples for this API implied that the return value from this
function was the port id of the newly created ethdev.

Since this latter behaviour is more useful - and already implied by the
documentation, this patch changes the return 0 to "return
data->port_id". It also adds in doxygen comments for the function so it
can be correctly documented in the API reference.

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/ring/rte_eth_ring.c |  9 +++++----
 drivers/net/ring/rte_eth_ring.h | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ring/rte_eth_ring.c b/drivers/net/ring/rte_eth_ring.c
index 6832f01..ada025f 100644
--- a/drivers/net/ring/rte_eth_ring.c
+++ b/drivers/net/ring/rte_eth_ring.c
@@ -346,7 +346,7 @@ rte_eth_from_rings(const char *name, struct rte_ring *const rx_queues[],
 	eth_dev->rx_pkt_burst = eth_ring_rx;
 	eth_dev->tx_pkt_burst = eth_ring_tx;
 
-	return 0;
+	return data->port_id;
 
 error:
 	rte_free(data);
@@ -384,7 +384,7 @@ eth_dev_ring_create(const char *name, const unsigned numa_node,
 			return -1;
 	}
 
-	if (rte_eth_from_rings(name, rxtx, num_rings, rxtx, num_rings, numa_node))
+	if (rte_eth_from_rings(name, rxtx, num_rings, rxtx, num_rings, numa_node) < 0)
 		return -1;
 
 	return 0;
@@ -424,8 +424,9 @@ eth_dev_ring_pair_create(const char *name, const unsigned numa_node,
 	}
 
 	if (rte_eth_from_rings(rx_rng_name, rx, num_rings, tx, num_rings,
-			numa_node) || rte_eth_from_rings(tx_rng_name, tx, num_rings, rx,
-					num_rings, numa_node))
+				numa_node) < 0 ||
+			rte_eth_from_rings(tx_rng_name, tx, num_rings, rx,
+				num_rings, numa_node) < 0)
 		return -1;
 
 	return 0;
diff --git a/drivers/net/ring/rte_eth_ring.h b/drivers/net/ring/rte_eth_ring.h
index d36489a..2262249 100644
--- a/drivers/net/ring/rte_eth_ring.h
+++ b/drivers/net/ring/rte_eth_ring.h
@@ -40,6 +40,24 @@ extern "C" {
 
 #include <rte_ring.h>
 
+/**
+ * Create a new ethdev port from a set of rings
+ *
+ * @param name
+ *    name to be given to the new ethdev port
+ * @param rx_queues
+ *    pointer to array of rte_rings to be used as RX queues
+ * @param nb_rx_queues
+ *    number of elements in the rx_queues array
+ * @param tx_queues
+ *    pointer to array of rte_rings to be used as TX queues
+ * @param nb_tx_queues
+ *    number of elements in the tx_queues array
+ * @param numa_node
+ *    the numa node on which the memory for this port is to be allocated
+ * @return
+ *    the port number of the newly created the ethdev or -1 on error.
+ */
 int rte_eth_from_rings(const char *name,
 		struct rte_ring * const rx_queues[],
 		const unsigned nb_rx_queues,
-- 
2.4.3