net: dsa: mv88e6xxx: Add erratum 3.14 for 88E6390X and 88E6190X

Fixes XAUI/RXAUI lane alignment errors.
Issue causes dropped packets when trying to communicate over
fiber via SERDES lanes of port 9 and 10.
Errata document applies only to 88E6190X and 88E6390X devices.
Requires poking in undocumented registers.

Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/mv88e6xxx/pcs-639x.c b/drivers/net/dsa/mv88e6xxx/pcs-639x.c
index 98dd49d..ba37365 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/pcs-639x.c
+++ b/drivers/net/dsa/mv88e6xxx/pcs-639x.c
@@ -20,6 +20,7 @@ struct mv88e639x_pcs {
        struct mdio_device mdio;
        struct phylink_pcs sgmii_pcs;
        struct phylink_pcs xg_pcs;
+       bool erratum_3_14;
        bool supports_5g;
        phy_interface_t interface;
        unsigned int irq;
@@ -205,13 +206,53 @@ static void mv88e639x_sgmii_pcs_pre_config(struct phylink_pcs *pcs,
        mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
 }
 
+static int mv88e6390_erratum_3_14(struct mv88e639x_pcs *mpcs)
+{
+       const int lanes[] = { MV88E6390_PORT9_LANE0, MV88E6390_PORT9_LANE1,
+               MV88E6390_PORT9_LANE2, MV88E6390_PORT9_LANE3,
+               MV88E6390_PORT10_LANE0, MV88E6390_PORT10_LANE1,
+               MV88E6390_PORT10_LANE2, MV88E6390_PORT10_LANE3 };
+       int err, i;
+
+       /* 88e6190x and 88e6390x errata 3.14:
+        * After chip reset, SERDES reconfiguration or SERDES core
+        * Software Reset, the SERDES lanes may not be properly aligned
+        * resulting in CRC errors
+        */
+
+       for (i = 0; i < ARRAY_SIZE(lanes); i++) {
+               err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
+                                       MDIO_MMD_PHYXS,
+                                       0xf054, 0x400C);
+               if (err)
+                       return err;
+
+               err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
+                                       MDIO_MMD_PHYXS,
+                                       0xf054, 0x4000);
+               if (err)
+                       return err;
+       }
+
+       return 0;
+}
+
 static int mv88e639x_sgmii_pcs_post_config(struct phylink_pcs *pcs,
                                           phy_interface_t interface)
 {
        struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
+       int err;
 
        mv88e639x_sgmii_pcs_control_pwr(mpcs, true);
 
+       if (mpcs->erratum_3_14) {
+               err = mv88e6390_erratum_3_14(mpcs);
+               if (err)
+                       dev_err(mpcs->mdio.dev.parent,
+                               "failed to apply erratum 3.14: %pe\n",
+                               ERR_PTR(err));
+       }
+
        return 0;
 }
 
@@ -524,6 +565,10 @@ static int mv88e6390_pcs_init(struct mv88e6xxx_chip *chip, int port)
        mpcs->xg_pcs.ops = &mv88e6390_xg_pcs_ops;
        mpcs->xg_pcs.neg_mode = true;
 
+       if (chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6190X ||
+           chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6390X)
+               mpcs->erratum_3_14 = true;
+
        err = mv88e639x_pcs_setup_irq(mpcs, chip, port);
        if (err)
                goto err_free;