r8169: fix infinite loop during hotplug

Bug reported for PCMCIA.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

drivers/net/r8169.c

@@ -2619,6 +2619,7 @@ static void rtl8169_down(struct net_device *dev)
 	struct rtl8169_private *tp = netdev_priv(dev);
 	void __iomem *ioaddr = tp->mmio_addr;
 	unsigned int poll_locked = 0;
+	unsigned int intrmask;
 
 	rtl8169_delete_timer(dev);
 
@@ -2657,8 +2658,11 @@ core_down:
 	 * 2) dev->change_mtu
 	 *    -> rtl8169_poll can not be issued again and re-enable the
 	 *       interruptions. Let's simply issue the IRQ down sequence again.
+	 *
+	 * No loop if hotpluged or major error (0xffff).
 	 */
-	if (RTL_R16(IntrMask))
+	intrmask = RTL_R16(IntrMask);
+	if (intrmask && (intrmask != 0xffff))
 		goto core_down;
 
 	rtl8169_tx_clear(tp);