3.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Amir Vadai <am...@mellanox.com>

commit a229e488ac3f904d06c20d8d3f47831db3c7a15a upstream.

Commit 37706996 "mlx4_en: fix allocation of CPU affinity reverse-map" fixed
a bug when mlx4_dev->caps.comp_pool is larger from the device rx rings, but
introduced a regression.

When the mlx4_core is activating its "legacy mode" (e.g when running in SRIOV
mode) w.r.t to EQs/IRQs usage, comp_pool becomes zero and we're crashing on
divide by zero alloc_cpu_rmap.

Fix that by enabling RFS only when running in non-legacy mode.

Reported-by: Yan Burman <y...@mellanox.com>
Cc: Kleber Sacilotto de Souza <kleb...@linux.vnet.ibm.com>
Signed-off-by: Amir Vadai <am...@mellanox.com>
Signed-off-by: Or Gerlitz <ogerl...@mellanox.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -1434,9 +1434,11 @@ int mlx4_en_alloc_resources(struct mlx4_
        }
 
 #ifdef CONFIG_RFS_ACCEL
-       priv->dev->rx_cpu_rmap = 
alloc_irq_cpu_rmap(priv->mdev->dev->caps.comp_pool);
-       if (!priv->dev->rx_cpu_rmap)
-               goto err;
+       if (priv->mdev->dev->caps.comp_pool) {
+               priv->dev->rx_cpu_rmap = 
alloc_irq_cpu_rmap(priv->mdev->dev->caps.comp_pool);
+               if (!priv->dev->rx_cpu_rmap)
+                       goto err;
+       }
 #endif
 
        return 0;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to