[PATCH 5.12 120/296] net/mlx5e: Fix error path of updating netdev queues

Greg Kroah-Hartman
2021-05-31T16:18:21Z

From: Aya Levin <ayal@nvidia.com>

commit 5e7923acbd86d0ff29269688d8a9c47ad091dd46 upstream.

Avoid division by zero in the error flow. In the driver TC number can be
either 1 or 8. When TC count is set to 1, driver zero netdev->num_tc.
Hence, need to convert it back from 0 to 1 in the error flow.

Fixes: fa3748775b92 ("net/mlx5e: Handle errors from netif_set_real_num_{tx,rx}_queues")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3027,7 +3027,7 @@ static int mlx5e_update_netdev_queues(st
int err;

old_num_txqs = netdev->real_num_tx_queues;
- old_ntc = netdev->num_tc;
+ old_ntc = netdev->num_tc ? : 1;

nch = priv->channels.params.num_channels;
ntc = priv->channels.params.num_tc;