r8152: avoid start_xmit to schedule napi when napi is disabled

BugLink: http://bugs.launchpad.net/bugs/1698817

[ Upstream commit de9bf29d ]

Stop the tx when the napi is disabled to prevent napi_schedule() is
called.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/net/usb/r8152.c

@@ -3066,10 +3066,13 @@ static void set_carrier(struct r8152 *tp)
 		if (!netif_carrier_ok(netdev)) {
 			tp->rtl_ops.enable(tp);
 			set_bit(RTL8152_SET_RX_MODE, &tp->flags);
+			netif_stop_queue(netdev);
 			napi_disable(&tp->napi);
 			netif_carrier_on(netdev);
 			rtl_start_rx(tp);
 			napi_enable(&tp->napi);
+			netif_wake_queue(netdev);
+			netif_info(tp, link, netdev, "carrier on\n");
 		}
 	} else {
 		if (netif_carrier_ok(netdev)) {
@@ -3077,6 +3080,7 @@ static void set_carrier(struct r8152 *tp)
 			napi_disable(&tp->napi);
 			tp->rtl_ops.disable(tp);
 			napi_enable(&tp->napi);
+			netif_info(tp, link, netdev, "carrier off\n");
 		}
 	}
 }
@@ -3461,12 +3465,12 @@ static int rtl8152_pre_reset(struct usb_interface *intf)
 	if (!netif_running(netdev))
 		return 0;
 
+	netif_stop_queue(netdev);
 	napi_disable(&tp->napi);
 	clear_bit(WORK_ENABLE, &tp->flags);
 	usb_kill_urb(tp->intr_urb);
 	cancel_delayed_work_sync(&tp->schedule);
 	if (netif_carrier_ok(netdev)) {
-		netif_stop_queue(netdev);
 		mutex_lock(&tp->control);
 		tp->rtl_ops.disable(tp);
 		mutex_unlock(&tp->control);
@@ -3494,10 +3498,10 @@ static int rtl8152_post_reset(struct usb_interface *intf)
 		rtl_start_rx(tp);
 		rtl8152_set_rx_mode(netdev);
 		mutex_unlock(&tp->control);
-		netif_wake_queue(netdev);
 	}
 
 	napi_enable(&tp->napi);
+	netif_wake_queue(netdev);
 	usb_submit_urb(tp->intr_urb, GFP_KERNEL);
 
 	return 0;