[dpdk-dev] [PATCH] net/mlx4: fix assertion failure on link update

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

The interrupt handler can sometimes be triggered for reasons other than a
link status event. An assertion failure happen when such events occur while
an asynchronous link status update is already scheduled.

Address this issue using the same approach as its mlx5 counterpart,
commit a9f2fbc42f0c ("net/mlx5: fix inconsistent link status")

Fixes: c4da6caa426d ("mlx4: handle link status interrupts")

Cc: stable@dpdk.org
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx4/mlx4.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 050d646..57b52ac 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -5343,6 +5343,7 @@ priv_dev_status_handler(struct priv *priv, struct rte_eth_dev *dev,
 {
 	struct ibv_async_event event;
 	int port_change = 0;
+	struct rte_eth_link *link = &dev->data->dev_link;
 	int ret = 0;
 
 	*events = 0;
@@ -5364,22 +5365,20 @@ priv_dev_status_handler(struct priv *priv, struct rte_eth_dev *dev,
 			      event.event_type, event.element.port_num);
 		ibv_ack_async_event(&event);
 	}
-
-	if (port_change ^ priv->pending_alarm) {
-		struct rte_eth_link *link = &dev->data->dev_link;
-
-		priv->pending_alarm = 0;
-		mlx4_link_update(dev, 0);
-		if (((link->link_speed == 0) && link->link_status) ||
-		    ((link->link_speed != 0) && !link->link_status)) {
+	if (!port_change)
+		return ret;
+	mlx4_link_update(dev, 0);
+	if (((link->link_speed == 0) && link->link_status) ||
+	    ((link->link_speed != 0) && !link->link_status)) {
+		if (!priv->pending_alarm) {
 			/* Inconsistent status, check again later. */
 			priv->pending_alarm = 1;
 			rte_eal_alarm_set(MLX4_ALARM_TIMEOUT_US,
 					  mlx4_dev_link_status_handler,
 					  dev);
-		} else {
-			*events |= (1 << RTE_ETH_EVENT_INTR_LSC);
 		}
+	} else {
+		*events |= (1 << RTE_ETH_EVENT_INTR_LSC);
 	}
 	return ret;
 }
@@ -5400,6 +5399,7 @@ mlx4_dev_link_status_handler(void *arg)
 
 	priv_lock(priv);
 	assert(priv->pending_alarm == 1);
+	priv->pending_alarm = 0;
 	ret = priv_dev_status_handler(priv, dev, &events);
 	priv_unlock(priv);
 	if (ret > 0 && events & (1 << RTE_ETH_EVENT_INTR_LSC))
-- 
2.1.4