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

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 < rx rings), cq->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 <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 14c00048bbec..82322b1c8411 100644
--- 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    */