ionic: Check stop no restart

If there is a lot of transmit traffic the driver can get into a
situation that the device is starved due to the doorbell never
being rung. This can happen if xmit_more is set constantly
and __netdev_tx_sent_queue() keeps returning false. Fix this
by checking if the queue needs to be stopped right before
calling __netdev_tx_sent_queue(). Use MAX_SKB_FRAGS + 1 as the
stop condition because that's the maximum number of frags
supported for non-TSO transmit.

Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 1397a0dcf794383118e8faf3a3da54d9c682d4f9..d9e23fc78e6b7a0959565a99b93a16a9ef99a86b 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -1665,9 +1665,14 @@ static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
        stats->pkts++;
        stats->bytes += skb->len;
 
-       if (!ionic_txq_hwstamp_enabled(q))
-               ring_dbell = __netdev_tx_sent_queue(q_to_ndq(q), skb->len,
+       if (!ionic_txq_hwstamp_enabled(q)) {
+               struct netdev_queue *ndq = q_to_ndq(q);
+
+               if (unlikely(!ionic_q_has_space(q, MAX_SKB_FRAGS + 1)))
+                       netif_tx_stop_queue(ndq);
+               ring_dbell = __netdev_tx_sent_queue(ndq, skb->len,
                                                    netdev_xmit_more());
+       }
        ionic_txq_post(q, ring_dbell, ionic_tx_clean, skb);
 
        return 0;