[PATCH net-next 2/3] net/mlx4_en: Align behavior of set ring size flow via ethtool

[Tariq Toukan <tariqt@mellanox.com>]

From: Eugenia Emantayev <eugenia@mellanox.com>

In current implementation, any requested RX/TX ring size value
that is less than minimum is silently casted to nearest valid value.
Update this behavior to align with mlx5 behavior by printing warning
in dmesg and remaining the size unchanged.
Kernel is responsible for verifying against the maximum.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index bf1f04164885..ebc1f566a4d9 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -1094,12 +1094,21 @@ static int mlx4_en_set_ringparam(struct net_device *dev,
 	if (param->rx_jumbo_pending || param->rx_mini_pending)
 		return -EINVAL;
 
+	if (param->rx_pending < MLX4_EN_MIN_RX_SIZE) {
+		en_warn(priv, "%s: rx_pending (%d) < min (%d)\n",
+			__func__, param->rx_pending,
+			MLX4_EN_MIN_RX_SIZE);
+		return -EINVAL;
+	}
+	if (param->tx_pending < MLX4_EN_MIN_TX_SIZE) {
+		en_warn(priv, "%s: tx_pending (%d) < min (%lu)\n",
+			__func__, param->tx_pending,
+			MLX4_EN_MIN_TX_SIZE);
+		return -EINVAL;
+	}
+
 	rx_size = roundup_pow_of_two(param->rx_pending);
-	rx_size = max_t(u32, rx_size, MLX4_EN_MIN_RX_SIZE);
-	rx_size = min_t(u32, rx_size, MLX4_EN_MAX_RX_SIZE);
 	tx_size = roundup_pow_of_two(param->tx_pending);
-	tx_size = max_t(u32, tx_size, MLX4_EN_MIN_TX_SIZE);
-	tx_size = min_t(u32, tx_size, MLX4_EN_MAX_TX_SIZE);
 
 	if (rx_size == (priv->port_up ? priv->rx_ring[0]->actual_size :
 					priv->rx_ring[0]->size) &&
-- 
1.8.3.1