This patch adds proper handling of the buggy revision A2 of LXT973 phy, adding
precautions linked to ERRATA Item 4:
Revision A2 of LXT973 chip randomly returns the contents of the previous even
register when you read a odd register regularly
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
diff -u a/drivers/net/phy/lxt.c b/drivers/net/phy/lxt.c
--- a/drivers/net/phy/lxt.c 2012-09-23 03:08:48.000000000 +0200
+++ b/drivers/net/phy/lxt.c 2012-09-23 03:18:00.000000000 +0200
@@ -122,6 +122,123 @@
return err;
}
+/*
+ * A2 version of LXT973 chip has an ERRATA: it randomly return the contents
+ * of the previous even register when you read a odd register regularly
+ */
+
+static int lxt973a2_update_link(struct phy_device *phydev)
+{
+ int status;
+ int control;
+ int retry = 8; /* we try 8 times */
+
+ /* Do a fake read */
+ status = phy_read(phydev, MII_BMSR);
+
+ if (status < 0)
+ return status;
+
+ control = phy_read(phydev, MII_BMCR);
+ if (control < 0)
+ return control;
+
+ do {
+ /* Read link and autonegotiation status */
+ status = phy_read(phydev, MII_BMSR);
+ } while (status >= 0 && retry-- && status == control);
+
+ if (status < 0)
+ return status;
+
+ if ((status & BMSR_LSTATUS) == 0)
+ phydev->link = 0;
+ else
+ phydev->link = 1;
+
+ return 0;
+}
+
+int lxt973a2_read_status(struct phy_device *phydev)
+{
+ int adv;
+ int err;
+ int lpa;
+ int lpagb = 0;
+
+ /* Update the link, but return if there was an error */
+ err = lxt973a2_update_link(phydev);
+ if (err)
+ return err;
+
+ if (AUTONEG_ENABLE == phydev->autoneg) {
+ int retry = 1;
+
+ adv = phy_read(phydev, MII_ADVERTISE);
+
+ if (adv < 0)
+ return adv;
+
+ do {
+ lpa = phy_read(phydev, MII_LPA);
+
+ if (lpa < 0)
+ return lpa;
+
+ /* If both registers are equal, it is suspect but not
+ * impossible, hence a new try
+ */
+ } while (lpa == adv && retry--);
+
+ lpa &= adv;
+
+ phydev->speed = SPEED_10;
+ phydev->duplex = DUPLEX_HALF;
+ phydev->pause = phydev->asym_pause = 0;
+
+ if (lpagb & (LPA_1000FULL | LPA_1000HALF)) {
+ phydev->speed = SPEED_1000;
+
+ if (lpagb & LPA_1000FULL)
+ phydev->duplex = DUPLEX_FULL;
+ } else if (lpa & (LPA_100FULL | LPA_100HALF)) {
+ phydev->speed = SPEED_100;
+
+ if (lpa & LPA_100FULL)
+ phydev->duplex = DUPLEX_FULL;
+ } else {
+ if (lpa & LPA_10FULL)
+ phydev->duplex = DUPLEX_FULL;
+ }
+
+ if (phydev->duplex == DUPLEX_FULL) {
+ phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;
+ phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;
+ }
+ } else {
+ int bmcr = phy_read(phydev, MII_BMCR);
+
+ if (bmcr < 0)
+ return bmcr;
+
+ if (bmcr & BMCR_FULLDPLX)
+ phydev->duplex = DUPLEX_FULL;
+ else
+ phydev->duplex = DUPLEX_HALF;
+
+ if (bmcr & BMCR_SPEED1000)
+ phydev->speed = SPEED_1000;
+ else if (bmcr & BMCR_SPEED100)
+ phydev->speed = SPEED_100;
+ else
+ phydev->speed = SPEED_10;
+
+ phydev->pause = phydev->asym_pause = 0;
+ }
+
+ return 0;
+}
+
static int lxt973_probe(struct phy_device *phydev)
{
int val = phy_read(phydev, MII_LXT973_PCR);
@@ -175,6 +292,16 @@
.driver = { .owner = THIS_MODULE,},
}, {
.phy_id = 0x00137a10,
+ .name = "LXT973-A2",
+ .phy_id_mask = 0xffffffff,
+ .features = PHY_BASIC_FEATURES,
+ .flags = 0,
+ .probe = lxt973_probe,
+ .config_aneg = lxt973_config_aneg,
+ .read_status = lxt973a2_read_status,
+ .driver = { .owner = THIS_MODULE,},
+}, {
+ .phy_id = 0x00137a10,
.name = "LXT973",
.phy_id_mask = 0xfffffff0,
.features = PHY_BASIC_FEATURES,
--
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