The MDIO read callback xgbe_phy_mii_read_c45() can propagate its return value up through phylink_mii_ioctl() to user space via netdev ioctls such as SIOCGMIIREG. Returning ENOTSUPP results in user space seeing "Unknown error", since ENOTSUPP is not a standard errno value. Replace ENOTSUPP with EOPNOTSUPP to align with the MDIO core’s usage and ensure user space receives a proper "Operation not supported" error instead of an unknown code. Fixes: 070f6186a2f1 ("amd-xgbe: Separate C22 and C45 transactions") Signed-off-by: Alok Tiwari --- drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c index a56efc1bee33..35a381a83647 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c @@ -668,7 +668,7 @@ static int xgbe_phy_mii_read_c45(struct mii_bus *mii, int addr, int devad, else if (phy_data->conn_type & XGBE_CONN_TYPE_MDIO) ret = xgbe_phy_mdio_mii_read_c45(pdata, addr, devad, reg); else - ret = -ENOTSUPP; + ret = -EOPNOTSUPP; xgbe_phy_put_comm_ownership(pdata); -- 2.50.1