[ 52/75] net/mlx4_en: Disable RFS when running in SRIOV mode

From: Greg Kroah-Hartman
Date: Mon Mar 18 2013 - 17:52:29 EST

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


From: Amir Vadai <amirv@xxxxxxxxxxxx>

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 <yanb@xxxxxxxxxxxx>
Cc: Kleber Sacilotto de Souza <klebers@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Amir Vadai <amirv@xxxxxxxxxxxx>
Signed-off-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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_

- 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;
+ }

return 0;

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