[dpdk-dev] [PATCH] net/dpaa2: enable Tx congestion state check

[Hemant Agrawal]

For larger packet size congestion is observed on Tx Queues.
This patch enables Tx Queue congestion state check support.
If congested, try to resend the packet few times.

Signed-off-by: Nipun Gupta <nipun.gupta at nxp.com>
Signed-off-by: Hemant Agrawal <hemant.agrawal at nxp.com>
---
 drivers/net/dpaa2/dpaa2_ethdev.c |  2 +-
 drivers/net/dpaa2/dpaa2_ethdev.h |  4 +++-
 drivers/net/dpaa2/dpaa2_rxtx.c   | 11 ++++++++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/net/dpaa2/dpaa2_ethdev.c b/drivers/net/dpaa2/dpaa2_ethdev.c
index c662505..429b3a0 100644
--- a/drivers/net/dpaa2/dpaa2_ethdev.c
+++ b/drivers/net/dpaa2/dpaa2_ethdev.c
@@ -488,7 +488,7 @@ dpaa2_dev_tx_queue_setup(struct rte_eth_dev *dev,
 	}
 	dpaa2_q->tc_index = tc_id;
 
-	if (priv->flags & DPAA2_TX_CGR_SUPPORT) {
+	if (!(priv->flags & DPAA2_TX_CGR_OFF)) {
 		struct dpni_congestion_notification_cfg cong_notif_cfg;
 
 		cong_notif_cfg.units = DPNI_CONGESTION_UNIT_FRAMES;
diff --git a/drivers/net/dpaa2/dpaa2_ethdev.h b/drivers/net/dpaa2/dpaa2_ethdev.h
index ea7c0db..a2902da 100644
--- a/drivers/net/dpaa2/dpaa2_ethdev.h
+++ b/drivers/net/dpaa2/dpaa2_ethdev.h
@@ -55,6 +55,8 @@
  */
 #define CONG_EXIT_TX_THRESHOLD    480
 
+#define CONG_RETRY_COUNT 18000
+
 /* RX queue tail drop threshold
  * currently considering 32 KB packets
  */
@@ -66,7 +68,7 @@
 /* Enable TX Congestion control support
  * default is disable
  */
-#define DPAA2_TX_CGR_SUPPORT	0x01
+#define DPAA2_TX_CGR_OFF	0x01
 
 /* Disable RX tail drop, default is enable */
 #define DPAA2_RX_TAILDROP_OFF	0x04
diff --git a/drivers/net/dpaa2/dpaa2_rxtx.c b/drivers/net/dpaa2/dpaa2_rxtx.c
index 3db91d8..3c057a3 100644
--- a/drivers/net/dpaa2/dpaa2_rxtx.c
+++ b/drivers/net/dpaa2/dpaa2_rxtx.c
@@ -524,7 +524,7 @@ uint16_t
 dpaa2_dev_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 {
 	/* Function to transmit the frames to given device and VQ*/
-	uint32_t loop;
+	uint32_t loop, retry_count;
 	int32_t ret;
 	struct qbman_fd fd_arr[MAX_TX_RING_SLOTS];
 	struct rte_mbuf *mi;
@@ -559,8 +559,13 @@ dpaa2_dev_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	/*Clear the unused FD fields before sending*/
 	while (nb_pkts) {
 		/*Check if the queue is congested*/
-		if (qbman_result_SCN_state_in_mem(dpaa2_q->cscn))
-			goto skip_tx;
+		retry_count = 0;
+		if (qbman_result_SCN_state_in_mem(dpaa2_q->cscn)) {
+			retry_count++;
+			/* Retry for some time before giving up */
+			if (retry_count > CONG_RETRY_COUNT)
+				goto skip_tx;
+		}
 
 		frames_to_send = (nb_pkts >> 3) ? MAX_TX_RING_SLOTS : nb_pkts;
 
-- 
2.7.4