Subject: [PATCH AUTOSEL 5.5 006/106] net/mlx5e: Enforce setting of a single FEC mode

From: Sasha Levin <[email-masked]>
Date: Wed, 15 Apr 2020 07:40:46 -0400

From: Aya Levin <[email-masked]>

[ Upstream commit 4bd9d5070b92da012f2715cf8e4859acb78b8f35 ]

Ethtool command allow setting of several FEC modes in a single set
command. The driver can only set a single FEC mode at a time. With this
patch driver will reply not-supported on setting several FEC modes.

Signed-off-by: Aya Levin <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index c6776f308d5e6..ce63f9bd10fa8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -1554,6 +1554,10 @@ static int mlx5e_set_fecparam(struct net_device *netdev,
 	int mode;
 	int err;
 
+	if (bitmap_weight((unsigned long *)&fecparam->fec,
+			  ETHTOOL_FEC_BASER_BIT + 1) > 1)
+		return -EOPNOTSUPP;
+
 	for (mode = 0; mode < ARRAY_SIZE(pplm_fec_2_ethtool); mode++) {
 		if (!(pplm_fec_2_ethtool[mode] & fecparam->fec))
 			continue;
-- 
2.20.1