[PATCH net-next 1/2] net: mvneta: add xmit_more support

[Marcin Wojtas]

From: Simon Guinot <simon.guinot at sequanux.org>

Basing on xmit_more flag of the skb, TX descriptors can be concatenated
before flushing. This commit delay Tx descriptor flush if the queue is
running and if there is more skb's to send.

Signed-off-by: Simon Guinot <simon.guinot at sequanux.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index d41c28d..b9dccea 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -512,6 +512,7 @@ struct mvneta_tx_queue {
 	 * descriptor ring
 	 */
 	int count;
+	int pending;
 	int tx_stop_threshold;
 	int tx_wake_threshold;
 
@@ -802,8 +803,9 @@ static void mvneta_txq_pend_desc_add(struct mvneta_port *pp,
 	/* Only 255 descriptors can be added at once ; Assume caller
 	 * process TX desriptors in quanta less than 256
 	 */
-	val = pend_desc;
+	val = pend_desc + txq->pending;
 	mvreg_write(pp, MVNETA_TXQ_UPDATE_REG(txq->id), val);
+	txq->pending = 0;
 }
 
 /* Get pointer to next TX descriptor to be processed (send) by HW */
@@ -2357,11 +2359,14 @@ out:
 		struct netdev_queue *nq = netdev_get_tx_queue(dev, txq_id);
 
 		txq->count += frags;
-		mvneta_txq_pend_desc_add(pp, txq, frags);
-
 		if (txq->count >= txq->tx_stop_threshold)
 			netif_tx_stop_queue(nq);
 
+		if (!skb->xmit_more || netif_xmit_stopped(nq))
+			mvneta_txq_pend_desc_add(pp, txq, frags);
+		else
+			txq->pending += frags;
+
 		u64_stats_update_begin(&stats->syncp);
 		stats->tx_packets++;
 		stats->tx_bytes  += len;
-- 
1.8.3.1