lan78xx: workaround of forced 100 Full/Half duplex mode error
At forced 100 Full & Half duplex mode, chip may fail to set mode correctly
when cable is switched between long(~50+m) and short one.
As workaround, set to 10 before setting to 100 at forced 100 F/H mode.
Signed-off-by: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 0460b81..f64778a 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1804,7 +1804,34 @@
static void lan78xx_link_status_change(struct net_device *net)
{
- /* nothing to do */
+ struct phy_device *phydev = net->phydev;
+ int ret, temp;
+
+ /* At forced 100 F/H mode, chip may fail to set mode correctly
+ * when cable is switched between long(~50+m) and short one.
+ * As workaround, set to 10 before setting to 100
+ * at forced 100 F/H mode.
+ */
+ if (!phydev->autoneg && (phydev->speed == 100)) {
+ /* disable phy interrupt */
+ temp = phy_read(phydev, LAN88XX_INT_MASK);
+ temp &= ~LAN88XX_INT_MASK_MDINTPIN_EN_;
+ ret = phy_write(phydev, LAN88XX_INT_MASK, temp);
+
+ temp = phy_read(phydev, MII_BMCR);
+ temp &= ~(BMCR_SPEED100 | BMCR_SPEED1000);
+ phy_write(phydev, MII_BMCR, temp); /* set to 10 first */
+ temp |= BMCR_SPEED100;
+ phy_write(phydev, MII_BMCR, temp); /* set to 100 later */
+
+ /* clear pending interrupt generated while workaround */
+ temp = phy_read(phydev, LAN88XX_INT_STS);
+
+ /* enable phy interrupt back */
+ temp = phy_read(phydev, LAN88XX_INT_MASK);
+ temp |= LAN88XX_INT_MASK_MDINTPIN_EN_;
+ ret = phy_write(phydev, LAN88XX_INT_MASK, temp);
+ }
}
static int lan78xx_phy_init(struct lan78xx_net *dev)