fix the large PPS skew bug which is introduced by crazy run of bitslide module.

    The bitslide module won't be reset when replugging the SFP and fiber, which may lead to
the wrong bitslide.

kernel/wr_nic/endpoint.c

@@ -101,7 +101,8 @@ static void wrn_update_link_status(struct net_device *dev)
 {
 	struct wrn_ep *ep = netdev_priv(dev);
 	u32 ecr, bmsr, bmcr, lpa;
-
+	uint32_t value;
+	
 	bmsr = wrn_phy_read(dev, 0, MII_BMSR);
 	bmcr = wrn_phy_read(dev, 0, MII_BMCR);
 
@@ -112,6 +113,9 @@ static void wrn_update_link_status(struct net_device *dev)
 	if (!mii_link_ok(&ep->mii)) {
 		if(netif_carrier_ok(dev)) {
 			netif_carrier_off(dev);
+			/* Reset SFP */
+			value = wrn_phy_read(dev, 0, MII_BMCR);
+			wrn_phy_write(dev, 0, MII_BMCR, value | BMCR_RESET);
 			clear_bit(WRN_EP_UP, &ep->ep_flags);
 			printk(KERN_INFO "%s: Link down.\n", dev->name);
 			return;