forcedeth: restart tx/rx

This patch fixes the issue where the transmitter and receiver must be
restarted when applying new changes to certain registers.
Signed-off-by: Ayaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/forcedeth.c

@@ -624,6 +624,9 @@ union ring_type {
 #define NV_MSI_X_VECTOR_TX    0x1
 #define NV_MSI_X_VECTOR_OTHER 0x2
 
+#define NV_RESTART_TX         0x1
+#define NV_RESTART_RX         0x2
+
 /* statistics */
 struct nv_ethtool_str {
 	char name[ETH_GSTRING_LEN];
@@ -2767,6 +2770,7 @@ static int nv_update_linkspeed(struct net_device *dev)
 	int mii_status;
 	int retval = 0;
 	u32 control_1000, status_1000, phyreg, pause_flags, txreg;
+	u32 txrxFlags = 0;
 
 	/* BMSR_LSTATUS is latched, read it twice:
 	 * we want the current value.
@@ -2862,6 +2866,16 @@ set_speed:
 	np->duplex = newdup;
 	np->linkspeed = newls;
 
+	/* The transmitter and receiver must be restarted for safe update */
+	if (readl(base + NvRegTransmitterControl) & NVREG_XMITCTL_START) {
+		txrxFlags |= NV_RESTART_TX;
+		nv_stop_tx(dev);
+	}
+	if (readl(base + NvRegReceiverControl) & NVREG_RCVCTL_START) {
+		txrxFlags |= NV_RESTART_RX;
+		nv_stop_rx(dev);
+	}
+
 	if (np->gigabit == PHY_GIGABIT) {
 		phyreg = readl(base + NvRegRandomSeed);
 		phyreg &= ~(0x3FF00);
@@ -2950,6 +2964,11 @@ set_speed:
 	}
 	nv_update_pause(dev, pause_flags);
 
+	if (txrxFlags & NV_RESTART_TX)
+		nv_start_tx(dev);
+	if (txrxFlags & NV_RESTART_RX)
+		nv_start_rx(dev);
+
 	return retval;
 }