net: phylink: allow attaching phy for SFP modules on 802.3z mode

Some SFPs may contain an internal PHY which may in some cases want to
connect with the host interface in 1000base-x/2500base-x mode.
Do not fail if such PHY is being attached in one of these PHY interface
modes.
Signed-off-by: NMarek Behún <kabel@kernel.org>
Reviewed-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NPali Rohár <pali@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/phylink.c

@@ -1669,7 +1669,7 @@ static int phylink_attach_phy(struct phylink *pl, struct phy_device *phy,
 {
 	if (WARN_ON(pl->cfg_link_an_mode == MLO_AN_FIXED ||
 		    (pl->cfg_link_an_mode == MLO_AN_INBAND &&
-		     phy_interface_mode_is_8023z(interface))))
+		     phy_interface_mode_is_8023z(interface) && !pl->sfp_bus)))
 		return -EINVAL;
 
 	if (pl->phydev)
@@ -2918,9 +2918,6 @@ static int phylink_sfp_config_phy(struct phylink *pl, u8 mode,
 		return ret;
 	}
 
-	if (phy_interface_mode_is_8023z(iface) && pl->phydev)
-		return -EINVAL;
-
 	pl->link_port = pl->sfp_port;
 
 	phylink_sfp_set_config(pl, mode, support, &config);