e1000e: bad state after running ethtool diagnostics with AMT enabled

When running ethtool online diagnostics with no open interface, there is a
short period of time where the driver relinquishes control of the adapter
during which time AMT (manageability firmware) can put the adapter into an
unknown state resulting in such things as link test failure, hardware hang,
reporting an incorrect link speed, etc.  Resetting the adapter during an
open() resolves this by putting the adapter into a quiescent state.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000e/ethtool.c

@@ -1737,6 +1737,12 @@ static void e1000_diag_test(struct net_device *netdev,
 		if (if_running)
 			dev_open(netdev);
 	} else {
+		if (!if_running && (adapter->flags & FLAG_HAS_AMT)) {
+			clear_bit(__E1000_TESTING, &adapter->state);
+			dev_open(netdev);
+			set_bit(__E1000_TESTING, &adapter->state);
+		}
+
 		e_info("online testing starting\n");
 		/* Online tests */
 		if (e1000_link_test(adapter, &data[4]))
@@ -1748,6 +1754,9 @@ static void e1000_diag_test(struct net_device *netdev,
 		data[2] = 0;
 		data[3] = 0;
 
+		if (!if_running && (adapter->flags & FLAG_HAS_AMT))
+			dev_close(netdev);
+
 		clear_bit(__E1000_TESTING, &adapter->state);
 	}
 	msleep_interruptible(4 * 1000);

drivers/net/e1000e/netdev.c

@@ -3444,20 +3444,22 @@ static int e1000_open(struct net_device *netdev)
 	if (err)
 		goto err_setup_rx;
 
+	/*
+	 * If AMT is enabled, let the firmware know that the network
+	 * interface is now open and reset the part to a known state.
+	 */
+	if (adapter->flags & FLAG_HAS_AMT) {
+		e1000_get_hw_control(adapter);
+		e1000e_reset(adapter);
+	}
+
 	e1000e_power_up_phy(adapter);
 
 	adapter->mng_vlan_id = E1000_MNG_VLAN_NONE;
 	if ((adapter->hw.mng_cookie.status &
 	     E1000_MNG_DHCP_COOKIE_STATUS_VLAN))
 		e1000_update_mng_vlan(adapter);
 
-	/*
-	 * If AMT is enabled, let the firmware know that the network
-	 * interface is now open
-	 */
-	if (adapter->flags & FLAG_HAS_AMT)
-		e1000_get_hw_control(adapter);
-
 	/*
 	 * before we allocate an interrupt, we must be ready to handle it.
 	 * Setting DEBUG_SHIRQ in the kernel makes it fire an interrupt