sky2: recovery deadlock fix

Prevent deadlock in sky2 recovery logic. sky2_down calls napi_synchronize
which gets stuck if napi was already disabled.

Fix by rearranging slightly and not calling napi_disable until after
both ports are stopped. The napi_disable probably is being overly
paranoid, but it is safe now.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/sky2.c

@@ -2906,16 +2906,14 @@ static void sky2_restart(struct work_struct *work)
 	int i, err;
 
 	rtnl_lock();
-	sky2_write32(hw, B0_IMSK, 0);
-	sky2_read32(hw, B0_IMSK);
-	napi_disable(&hw->napi);
-
 	for (i = 0; i < hw->ports; i++) {
 		dev = hw->dev[i];
 		if (netif_running(dev))
 			sky2_down(dev);
 	}
 
+	napi_disable(&hw->napi);
+	sky2_write32(hw, B0_IMSK, 0);
 	sky2_reset(hw);
 	sky2_write32(hw, B0_IMSK, Y2_IS_BASE);
 	napi_enable(&hw->napi);