Merge branch 'mv88e6xxx-fixes-for-reading-serdes-state'

Russell King says:

====================
mv88e6xxx: fixes for reading serdes state

These are some low-priority fixes to the mv88e6xxx serdes code.
Patch 1 fixes the reporting of an_complete, which is used in the
emulation of a conventional C22 PHY. Patch from Marek.

Patch 2 makes one of the error messages in patch 2 to be consistent
with the other error messages in this function.

Patch 3 ensures that we do not miss a link-failure event.
====================

Link: https://lore.kernel.org/r/Yp82TyoLon9jz6k3@shell.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mv88e6xxx/serdes.c

@@ -50,22 +50,25 @@ static int mv88e6390_serdes_write(struct mv88e6xxx_chip *chip,
 }
 
 static int mv88e6xxx_serdes_pcs_get_state(struct mv88e6xxx_chip *chip,
-					  u16 ctrl, u16 status, u16 lpa,
+					  u16 bmsr, u16 lpa, u16 status,
 					  struct phylink_link_state *state)
 {
+	state->link = false;
+
+	/* If the BMSR reports that the link had failed, report this to
+	 * phylink.
+	 */
+	if (!(bmsr & BMSR_LSTATUS))
+		return 0;
+
 	state->link = !!(status & MV88E6390_SGMII_PHY_STATUS_LINK);
+	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
 
 	if (status & MV88E6390_SGMII_PHY_STATUS_SPD_DPL_VALID) {
 		/* The Spped and Duplex Resolved register is 1 if AN is enabled
 		 * and complete, or if AN is disabled. So with disabled AN we
-		 * still get here on link up. But we want to set an_complete
-		 * only if AN was enabled, thus we look at BMCR_ANENABLE.
-		 * (According to 802.3-2008 section 22.2.4.2.10, we should be
-		 *  able to get this same value from BMSR_ANEGCAPABLE, but tests
-		 *  show that these Marvell PHYs don't conform to this part of
-		 *  the specificaion - BMSR_ANEGCAPABLE is simply always 1.)
+		 * still get here on link up.
 		 */
-		state->an_complete = !!(ctrl & BMCR_ANENABLE);
 		state->duplex = status &
 				MV88E6390_SGMII_PHY_STATUS_DUPLEX_FULL ?
 			                         DUPLEX_FULL : DUPLEX_HALF;
@@ -191,12 +194,12 @@ int mv88e6352_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
 int mv88e6352_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 				   int lane, struct phylink_link_state *state)
 {
-	u16 lpa, status, ctrl;
+	u16 bmsr, lpa, status;
 	int err;
 
-	err = mv88e6352_serdes_read(chip, MII_BMCR, &ctrl);
+	err = mv88e6352_serdes_read(chip, MII_BMSR, &bmsr);
 	if (err) {
-		dev_err(chip->dev, "can't read Serdes PHY control: %d\n", err);
+		dev_err(chip->dev, "can't read Serdes PHY BMSR: %d\n", err);
 		return err;
 	}
 
@@ -212,7 +215,7 @@ int mv88e6352_serdes_pcs_get_state(struct mv88e6xxx_chip *chip, int port,
 		return err;
 	}
 
-	return mv88e6xxx_serdes_pcs_get_state(chip, ctrl, status, lpa, state);
+	return mv88e6xxx_serdes_pcs_get_state(chip, bmsr, lpa, status, state);
 }
 
 int mv88e6352_serdes_pcs_an_restart(struct mv88e6xxx_chip *chip, int port,
@@ -918,13 +921,13 @@ int mv88e6390_serdes_pcs_config(struct mv88e6xxx_chip *chip, int port,
 static int mv88e6390_serdes_pcs_get_state_sgmii(struct mv88e6xxx_chip *chip,
 	int port, int lane, struct phylink_link_state *state)
 {
-	u16 lpa, status, ctrl;
+	u16 bmsr, lpa, status;
 	int err;
 
 	err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
-				    MV88E6390_SGMII_BMCR, &ctrl);
+				    MV88E6390_SGMII_BMSR, &bmsr);
 	if (err) {
-		dev_err(chip->dev, "can't read Serdes PHY control: %d\n", err);
+		dev_err(chip->dev, "can't read Serdes PHY BMSR: %d\n", err);
 		return err;
 	}
 
@@ -942,7 +945,7 @@ static int mv88e6390_serdes_pcs_get_state_sgmii(struct mv88e6xxx_chip *chip,
 		return err;
 	}
 
-	return mv88e6xxx_serdes_pcs_get_state(chip, ctrl, status, lpa, state);
+	return mv88e6xxx_serdes_pcs_get_state(chip, bmsr, lpa, status, state);
 }
 
 static int mv88e6390_serdes_pcs_get_state_10g(struct mv88e6xxx_chip *chip,