[PATCH] subdance: fix TX Pause bug (reset_tx, intr_handler)

Fix TX Pause bug (reset_tx, intr_handler).  When MaxCollisions occurred, need
to re-enable Tx.  But just after re-enable, MaxCollisions maybe occurred again
and with TxStatusOverflow.  This will cause driver can't check new
MaxCollisions to re-enable Tx again, because TxStatusOverflow.  For this
reason, after re-enable Tx, we need to make sure Tx was actually enabled.
Signed-off-by: NJesse Huang <jesse@icplus.com.tw>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/sundance.c

@@ -1079,6 +1079,8 @@ reset_tx (struct net_device *dev)
 
 	/* free all tx skbuff */
 	for (i = 0; i < TX_RING_SIZE; i++) {
+		np->tx_ring[i].next_desc = 0;
+
 		skb = np->tx_skbuff[i];
 		if (skb) {
 			pci_unmap_single(np->pci_dev,
@@ -1094,6 +1096,10 @@ reset_tx (struct net_device *dev)
 	}
 	np->cur_tx = np->dirty_tx = 0;
 	np->cur_task = 0;
+
+	np->last_tx = 0;
+	iowrite8(127, ioaddr + TxDMAPollPeriod);
+
 	iowrite16 (StatsEnable | RxEnable | TxEnable, ioaddr + MACCtrl1);
 	return 0;
 }
@@ -1162,8 +1168,14 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
 						sundance_reset(dev, (NetworkReset|FIFOReset|TxReset) << 16);
 						/* No need to reset the Tx pointer here */
 					}
-					/* Restart the Tx. */
-					iowrite16 (TxEnable, ioaddr + MACCtrl1);
+					/* Restart the Tx. Need to make sure tx enabled */
+					i = 10;
+					do {
+						iowrite16(ioread16(ioaddr + MACCtrl1) | TxEnable, ioaddr + MACCtrl1);
+						if (ioread16(ioaddr + MACCtrl1) & TxEnabled)
+							break;
+						mdelay(1);
+					} while (--i);
 				}
 				/* Yup, this is a documentation bug.  It cost me *hours*. */
 				iowrite16 (0, ioaddr + TxStatus);