From: Eugenia Emantayev <eugenia@mellanox.com>
Date: Mon, 8 Jan 2018 16:00:25 +0200
Subject: net/mlx4_en: Align behavior of set ring size flow via ethtool
Patch-mainline: v4.16-rc1
Git-commit: 7589fd5c8c2802c370f18ab5a9c571eb34aa9a35
References: bsc#1103989 FATE#326004

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c |   17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

--- 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
 	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) &&