e1000: rework driver hardware reset locking

After studying the driver mac reset code it was found that there
were multiple race conditions possible to reset the unit twice or
bring it e1000_up() double. This fixes all occurences where the
driver needs to reset the mac.

We also remove irq requesting/releasing into _open and _close so
that while the device is _up we will never touch the irq's. This fixes
the double free irq bug that people saw.

To make sure that the watchdog task doesn't cause another race we let
it run as a non-scheduled task.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c
index 845d293..cf5c5f4 100644
--- a/drivers/net/e1000/e1000_ethtool.c
+++ b/drivers/net/e1000/e1000_ethtool.c
@@ -203,11 +203,9 @@
 
 	/* reset the link */
 
-	if (netif_running(adapter->netdev)) {
-		e1000_down(adapter);
-		e1000_reset(adapter);
-		e1000_up(adapter);
-	} else
+	if (netif_running(adapter->netdev))
+		e1000_reinit_locked(adapter);
+	else
 		e1000_reset(adapter);
 
 	return 0;
@@ -254,10 +252,9 @@
 	hw->original_fc = hw->fc;
 
 	if (adapter->fc_autoneg == AUTONEG_ENABLE) {
-		if (netif_running(adapter->netdev)) {
-			e1000_down(adapter);
-			e1000_up(adapter);
-		} else
+		if (netif_running(adapter->netdev))
+			e1000_reinit_locked(adapter);
+		else
 			e1000_reset(adapter);
 	} else
 		return ((hw->media_type == e1000_media_type_fiber) ?
@@ -279,10 +276,9 @@
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	adapter->rx_csum = data;
 
-	if (netif_running(netdev)) {
-		e1000_down(adapter);
-		e1000_up(adapter);
-	} else
+	if (netif_running(netdev))
+		e1000_reinit_locked(adapter);
+	else
 		e1000_reset(adapter);
 	return 0;
 }
@@ -631,6 +627,9 @@
 	tx_ring_size = sizeof(struct e1000_tx_ring) * adapter->num_tx_queues;
 	rx_ring_size = sizeof(struct e1000_rx_ring) * adapter->num_rx_queues;
 
+	while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
+		msleep(1);
+
 	if (netif_running(adapter->netdev))
 		e1000_down(adapter);
 
@@ -691,9 +690,11 @@
 		adapter->rx_ring = rx_new;
 		adapter->tx_ring = tx_new;
 		if ((err = e1000_up(adapter)))
-			return err;
+			goto err_setup;
 	}
 
+	clear_bit(__E1000_RESETTING, &adapter->flags);
+
 	return 0;
 err_setup_tx:
 	e1000_free_all_rx_resources(adapter);
@@ -701,6 +702,8 @@
 	adapter->rx_ring = rx_old;
 	adapter->tx_ring = tx_old;
 	e1000_up(adapter);
+err_setup:
+	clear_bit(__E1000_RESETTING, &adapter->flags);
 	return err;
 }
 
@@ -1568,6 +1571,7 @@
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	boolean_t if_running = netif_running(netdev);
 
+	set_bit(__E1000_DRIVER_TESTING, &adapter->flags);
 	if (eth_test->flags == ETH_TEST_FL_OFFLINE) {
 		/* Offline tests */
 
@@ -1582,7 +1586,8 @@
 			eth_test->flags |= ETH_TEST_FL_FAILED;
 
 		if (if_running)
-			e1000_down(adapter);
+			/* indicate we're in test mode */
+			dev_close(netdev);
 		else
 			e1000_reset(adapter);
 
@@ -1607,8 +1612,9 @@
 		adapter->hw.autoneg = autoneg;
 
 		e1000_reset(adapter);
+		clear_bit(__E1000_DRIVER_TESTING, &adapter->flags);
 		if (if_running)
-			e1000_up(adapter);
+			dev_open(netdev);
 	} else {
 		/* Online tests */
 		if (e1000_link_test(adapter, &data[4]))
@@ -1619,6 +1625,8 @@
 		data[1] = 0;
 		data[2] = 0;
 		data[3] = 0;
+
+		clear_bit(__E1000_DRIVER_TESTING, &adapter->flags);
 	}
 	msleep_interruptible(4 * 1000);
 }
@@ -1807,10 +1815,8 @@
 e1000_nway_reset(struct net_device *netdev)
 {
 	struct e1000_adapter *adapter = netdev_priv(netdev);
-	if (netif_running(netdev)) {
-		e1000_down(adapter);
-		e1000_up(adapter);
-	}
+	if (netif_running(netdev))
+		e1000_reinit_locked(adapter);
 	return 0;
 }