net/mlx4_en: cq->irq_desc wasn't set in legacy EQ's

amirv · davem330 · commit 858e6c321065 · 2014-07-16T23:28:32.000-07:00
Fix a regression introduced by commit 35f6f45 ("net/mlx4_en: Don't use
irq_affinity_notifier to track changes in IRQ affinity map").
When core is started in legacy EQ's (number of IRQ's &lt; rx rings), cq-&gt;irq_desc
was NULL.  This caused a kernel crash under heavy traffic - when having more
than rx NAPI budget completions.
Fixed to have it set for both EQ modes.

Signed-off-by: Amir Vadai &lt;amirv@mellanox.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -129,14 +129,15 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
 						  name);
 				}
 
-				cq->irq_desc =
-					irq_to_desc(mlx4_eq_get_irq(mdev->dev,
-								    cq->vector));
 			}
 		} else {
 			cq->vector = (cq->ring + 1 + priv->port) %
 				mdev->dev->caps.num_comp_vectors;
 		}
+
+		cq->irq_desc =
+			irq_to_desc(mlx4_eq_get_irq(mdev->dev,
+						    cq->vector));
 	} else {
 		/* For TX we use the same irq per
 		ring we assigned for the RX    */

Original file line number	Diff line number	Diff line change
`@@ -129,14 +129,15 @@ int mlx4_en_activate_cq(struct mlx4_en_priv priv, struct mlx4_en_cq cq,`
`129`	`129`	`name);`
`130`	`130`	`}`
`131`	`131`
`132`		`- cq->irq_desc =`
`133`		`- irq_to_desc(mlx4_eq_get_irq(mdev->dev,`
`134`		`- cq->vector));`
`135`	`132`	`}`
`136`	`133`	`} else {`
`137`	`134`	`cq->vector = (cq->ring + 1 + priv->port) %`
`138`	`135`	`mdev->dev->caps.num_comp_vectors;`
`139`	`136`	`}`
	`137`	`+`
	`138`	`+ cq->irq_desc =`
	`139`	`+ irq_to_desc(mlx4_eq_get_irq(mdev->dev,`
	`140`	`+ cq->vector));`
`140`	`141`	`} else {`
`141`	`142`	`/* For TX we use the same irq per`
`142`	`143`	`ring we assigned for the RX */`