[PATCH net] net: pcs: xpcs-rk: limit advertised interfaces

[Coia Prant]

The RK3568 XPCS supports 1000BASE-X, SGMII and QSGMII, but the RK3568
GMAC only implements SGMII, so only SGMII is advertised in
supported_interfaces.

The generic xpcs core fills the mask from the compat table, which
includes 1000BASE-X, QSGMII and the higher-speed modes. Clearing it and
setting only SGMII keeps phylink from validating interfaces that are
not usable here.

1000BASE-X and QSGMII can be enabled later when a board actually wires
them up.

Signed-off-by: Coia Prant <coiaprant at gmail.com>
---
 drivers/net/pcs/pcs-xpcs-rk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/pcs/pcs-xpcs-rk.c b/drivers/net/pcs/pcs-xpcs-rk.c
index 6f0a110e32d2..cc11a70d624f 100644
--- a/drivers/net/pcs/pcs-xpcs-rk.c
+++ b/drivers/net/pcs/pcs-xpcs-rk.c
@@ -536,6 +536,12 @@ struct dw_xpcs *xpcs_rk_create(struct device *dev, struct device_node *pcs, int
 		return xpcs;
 	}
 
+	/*
+	 * The RK3568 XPCS supports 1000BASE-X, SGMII and QSGMII.
+	 */
+	phy_interface_zero(xpcs->pcs.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_SGMII, xpcs->pcs.supported_interfaces);
+
 	xpcs_config_eee_mult_fact(xpcs, pxpcs->eee_mult_fact);
 	put_device(&pdev->dev);
 	return xpcs;
-- 
2.47.3