ixgbevf: Fix ordering of shutdown to correctly disable Rx and Tx

This patch updates the ordering of the shutdown path so that we attempt to
shutdown the rings more gracefully. Basically the big changes are that we
shutdown the main Rx filter in the case of Rx and we set the carrier_off
state in the case of Tx so that packets stop being delivered from outside
the driver.  Then we shut down interrupts and NAPI.  Finally we stop the
rings from performing DMA and clean them.  This is a bit more graceful than
the previous path.

CC: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

@@ -1957,6 +1957,10 @@ static void ixgbevf_up_complete(struct ixgbevf_adapter *adapter)
 	clear_bit(__IXGBEVF_DOWN, &adapter->state);
 	ixgbevf_napi_enable_all(adapter);
 
+	/* clear any pending interrupts, may auto mask */
+	IXGBE_READ_REG(hw, IXGBE_VTEICR);
+	ixgbevf_irq_enable(adapter);
+
 	/* enable transmits */
 	netif_tx_start_all_queues(netdev);
 
@@ -1969,16 +1973,9 @@ static void ixgbevf_up_complete(struct ixgbevf_adapter *adapter)
 
 void ixgbevf_up(struct ixgbevf_adapter *adapter)
 {
-	struct ixgbe_hw *hw = &adapter->hw;
-
 	ixgbevf_configure(adapter);
 
 	ixgbevf_up_complete(adapter);
-
-	/* clear any pending interrupts, may auto mask */
-	IXGBE_READ_REG(hw, IXGBE_VTEICR);
-
-	ixgbevf_irq_enable(adapter);
 }
 
 /**
@@ -2085,17 +2082,20 @@ void ixgbevf_down(struct ixgbevf_adapter *adapter)
 	for (i = 0; i < adapter->num_rx_queues; i++)
 		ixgbevf_disable_rx_queue(adapter, adapter->rx_ring[i]);
 
-	netif_tx_disable(netdev);
-
-	msleep(10);
+	usleep_range(10000, 20000);
 
 	netif_tx_stop_all_queues(netdev);
 
+	/* call carrier off first to avoid false dev_watchdog timeouts */
+	netif_carrier_off(netdev);
+	netif_tx_disable(netdev);
+
 	ixgbevf_irq_disable(adapter);
 
 	ixgbevf_napi_disable_all(adapter);
 
 	del_timer_sync(&adapter->watchdog_timer);
+
 	/* can't call flush scheduled work here because it can deadlock
 	 * if linkwatch_event tries to acquire the rtnl_lock which we are
 	 * holding */
@@ -2110,8 +2110,6 @@ void ixgbevf_down(struct ixgbevf_adapter *adapter)
 				IXGBE_TXDCTL_SWFLSH);
 	}
 
-	netif_carrier_off(netdev);
-
 	if (!pci_channel_offline(adapter->pdev))
 		ixgbevf_reset(adapter);
 
@@ -2995,10 +2993,6 @@ static int ixgbevf_open(struct net_device *netdev)
 	if (!adapter->num_msix_vectors)
 		return -ENOMEM;
 
-	/* disallow open during test */
-	if (test_bit(__IXGBEVF_TESTING, &adapter->state))
-		return -EBUSY;
-
 	if (hw->adapter_stopped) {
 		ixgbevf_reset(adapter);
 		/* if adapter is still stopped then PF isn't up and
@@ -3011,6 +3005,12 @@ static int ixgbevf_open(struct net_device *netdev)
 		}
 	}
 
+	/* disallow open during test */
+	if (test_bit(__IXGBEVF_TESTING, &adapter->state))
+		return -EBUSY;
+
+	netif_carrier_off(netdev);
+
 	/* allocate transmit descriptors */
 	err = ixgbevf_setup_all_tx_resources(adapter);
 	if (err)
@@ -3030,15 +3030,11 @@ static int ixgbevf_open(struct net_device *netdev)
 	 */
 	ixgbevf_map_rings_to_vectors(adapter);
 
-	ixgbevf_up_complete(adapter);
-
-	/* clear any pending interrupts, may auto mask */
-	IXGBE_READ_REG(hw, IXGBE_VTEICR);
 	err = ixgbevf_request_irq(adapter);
 	if (err)
 		goto err_req_irq;
 
-	ixgbevf_irq_enable(adapter);
+	ixgbevf_up_complete(adapter);
 
 	return 0;