net: phylink: handle MDIO_USXGMII_LINK when decoding USXGMII

If MDIO_USXGMII_LINK is not set, it means that the PHYs media side
link is down. Indicate back to phylink that the link as a whole is
down.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index eb8dd57e30f7..57feda626b41 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -3842,12 +3842,18 @@ static void phylink_decode_sgmii_word(struct phylink_link_state *state,
  * @lpa: a 16 bit value which stores the USXGMII auto-negotiation word
  *
  * Helper for MAC PCS supporting the USXGMII protocol and the auto-negotiation
- * code word.  Decode the USXGMII code word and populate the corresponding fields
- * (speed, duplex) into the phylink_link_state structure.
+ * code word. Decode the USXGMII code word and populate the corresponding fields
+ * (speed, duplex) into the phylink_link_state structure. If the code word
+ * indicates link is down, or we are unable to decode it, set the link down.
  */
 void phylink_decode_usxgmii_word(struct phylink_link_state *state,
 				 uint16_t lpa)
 {
+	if (!(lpa & MDIO_USXGMII_LINK)) {
+		state->link = false;
+		return;
+	}
+
 	switch (lpa & MDIO_USXGMII_SPD_MASK) {
 	case MDIO_USXGMII_10:
 		state->speed = SPEED_10;