diff --git a/drivers/net/ethernet/mellanox/mlxsw/reg.h b/drivers/net/ethernet/mellanox/mlxsw/reg.h
index 16e2df6ef2f48edead0736aded2a2a32abb336cb..c4adc7f740d3e6b8a6c2f50b399846cbd2ecacbd 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/reg.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/reg.h
@@ -4430,6 +4430,7 @@ MLXSW_ITEM32(reg, ptys, ext_eth_proto_cap, 0x08, 0, 32);
 #define MLXSW_REG_PTYS_ETH_SPEED_100GBASE_CR4		BIT(20)
 #define MLXSW_REG_PTYS_ETH_SPEED_100GBASE_SR4		BIT(21)
 #define MLXSW_REG_PTYS_ETH_SPEED_100GBASE_KR4		BIT(22)
+#define MLXSW_REG_PTYS_ETH_SPEED_100GBASE_LR4_ER4	BIT(23)
 #define MLXSW_REG_PTYS_ETH_SPEED_25GBASE_CR		BIT(27)
 #define MLXSW_REG_PTYS_ETH_SPEED_25GBASE_KR		BIT(28)
 #define MLXSW_REG_PTYS_ETH_SPEED_25GBASE_SR		BIT(29)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
index bd7f873f6290b3e74fcf49c747fee4280e99d0cf..0bd64169bf8121c6c39f19be9ba8add48bf3374f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
@@ -1169,6 +1169,11 @@ static const struct mlxsw_sp1_port_link_mode mlxsw_sp1_port_link_mode[] = {
 		.mask_ethtool	= ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT,
 		.speed		= SPEED_100000,
 	},
+	{
+		.mask		= MLXSW_REG_PTYS_ETH_SPEED_100GBASE_LR4_ER4,
+		.mask_ethtool	= ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT,
+		.speed		= SPEED_100000,
+	},
 };
 
 #define MLXSW_SP1_PORT_LINK_MODE_LEN ARRAY_SIZE(mlxsw_sp1_port_link_mode)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/switchx2.c b/drivers/net/ethernet/mellanox/mlxsw/switchx2.c
index 40e2e79d451798eb7009a1de733fd4372893f223..131b2a53d261d64b5ff2d19cbe68741eead7d469 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/switchx2.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/switchx2.c
@@ -613,7 +613,8 @@ static const struct mlxsw_sx_port_link_mode mlxsw_sx_port_link_mode[] = {
 	{
 		.mask		= MLXSW_REG_PTYS_ETH_SPEED_100GBASE_CR4 |
 				  MLXSW_REG_PTYS_ETH_SPEED_100GBASE_SR4 |
-				  MLXSW_REG_PTYS_ETH_SPEED_100GBASE_KR4,
+				  MLXSW_REG_PTYS_ETH_SPEED_100GBASE_KR4 |
+				  MLXSW_REG_PTYS_ETH_SPEED_100GBASE_LR4_ER4,
 		.speed		= 100000,
 	},
 };