forcedeth: preserve registers

Various registers need to be preserved before resetting the device.
Signed-off-by: NAyaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/forcedeth.c

@@ -1435,16 +1435,30 @@ static void nv_mac_reset(struct net_device *dev)
 {
 	struct fe_priv *np = netdev_priv(dev);
 	u8 __iomem *base = get_hwbase(dev);
+	u32 temp1, temp2, temp3;
 
 	dprintk(KERN_DEBUG "%s: nv_mac_reset\n", dev->name);
+
 	writel(NVREG_TXRXCTL_BIT2 | NVREG_TXRXCTL_RESET | np->txrxctl_bits, base + NvRegTxRxControl);
 	pci_push(base);
+
+	/* save registers since they will be cleared on reset */
+	temp1 = readl(base + NvRegMacAddrA);
+	temp2 = readl(base + NvRegMacAddrB);
+	temp3 = readl(base + NvRegTransmitPoll);
+
 	writel(NVREG_MAC_RESET_ASSERT, base + NvRegMacReset);
 	pci_push(base);
 	udelay(NV_MAC_RESET_DELAY);
 	writel(0, base + NvRegMacReset);
 	pci_push(base);
 	udelay(NV_MAC_RESET_DELAY);
+
+	/* restore saved registers */
+	writel(temp1, base + NvRegMacAddrA);
+	writel(temp2, base + NvRegMacAddrB);
+	writel(temp3, base + NvRegTransmitPoll);
+
 	writel(NVREG_TXRXCTL_BIT2 | np->txrxctl_bits, base + NvRegTxRxControl);
 	pci_push(base);
 }