r8169: fix invalid register dump

For some reason, my PCIe RTL8111E onboard NIC on a GA-Z68X-UD3H-B3
motherboard reads as FFs when reading from MMIO with a block size
larger than 7. Therefore change to reading blocks of four bytes.

Ben Hutchings noted that the buffer is large enough to hold all
registers, so now all registers are read.

Signed-off-by: Peter Wu <lekensteyn@gmail.com>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -1897,9 +1897,13 @@ static void rtl8169_get_regs(struct net_device *dev, struct ethtool_regs *regs,
 			     void *p)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
+	u32 __iomem *data = tp->mmio_addr;
+	u32 *dw = p;
+	int i;
 
 	rtl_lock_work(tp);
-	memcpy_fromio(p, tp->mmio_addr, regs->len);
+	for (i = 0; i < R8169_REGS_SIZE; i += 4)
+		memcpy_fromio(dw++, data++, 4);
 	rtl_unlock_work(tp);
 }