Merge branch 'r8152-napi-fixes'

Hayes Wang says:

====================
r8152: fix scheduling napi

v3:
simply the argument for patch #3. Replace &tp->napi with napi.

v2:
Add smp_mb__after_atomic() for patch #1.

v1:
Scheduling the napi during the following periods would let it be ignored.
And the events wouldn't be handled until next napi_schedule() is called.

1. after napi_disable and before napi_enable().
2. after all actions of napi function is completed and before calling
   napi_complete().

If no next napi_schedule() is called, tx or rx would stop working.

In order to avoid these situations, the followings solutions are applied.

1. prevent start_xmit() from calling napi_schedule() during runtime suspend
   or after napi_disable().
2. re-schedule the napi for tx if it is necessary.
3. check if any rx is finished or not after napi_enable().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Author: davem330

drivers/net/usb/r8152.c

@@ -32,7 +32,7 @@
 #define NETNEXT_VERSION		"08"
 
 /* Information for net */
-#define NET_VERSION		"7"
+#define NET_VERSION		"8"
 
 #define DRIVER_VERSION		"v1." NETNEXT_VERSION "." NET_VERSION
 #define DRIVER_AUTHOR "Realtek linux nic maintainers <nic_swsd@realtek.com>"
@@ -1936,6 +1936,9 @@ static int r8152_poll(struct napi_struct *napi, int budget)
 		napi_complete(napi);
 		if (!list_empty(&tp->rx_done))
 			napi_schedule(napi);
+		else if (!skb_queue_empty(&tp->tx_queue) &&
+			 !list_empty(&tp->tx_free))
+			napi_schedule(napi);
 	}
 
 	return work_done;
@@ -3155,17 +3158,21 @@ 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)) {
 			netif_carrier_off(netdev);
 			napi_disable(&tp->napi);
 			tp->rtl_ops.disable(tp);
 			napi_enable(&tp->napi);
+			netif_info(tp, link, netdev, "carrier off\n");
 		}
 	}
 }
@@ -3515,12 +3522,12 @@ 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);
@@ -3548,12 +3555,15 @@ 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);
 
+	if (!list_empty(&tp->rx_done))
+		napi_schedule(&tp->napi);
+
 	return 0;
 }
 
@@ -3585,10 +3595,15 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
 	struct net_device *netdev = tp->netdev;
 	int ret = 0;
 
+	set_bit(SELECTIVE_SUSPEND, &tp->flags);
+	smp_mb__after_atomic();
+
 	if (netif_running(netdev) && test_bit(WORK_ENABLE, &tp->flags)) {
 		u32 rcr = 0;
 
 		if (delay_autosuspend(tp)) {
+			clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+			smp_mb__after_atomic();
 			ret = -EBUSY;
 			goto out1;
 		}
@@ -3605,6 +3620,8 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
 			if (!(ocp_data & RXFIFO_EMPTY)) {
 				rxdy_gated_en(tp, false);
 				ocp_write_dword(tp, MCU_TYPE_PLA, PLA_RCR, rcr);
+				clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+				smp_mb__after_atomic();
 				ret = -EBUSY;
 				goto out1;
 			}
@@ -3624,8 +3641,6 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
 		}
 	}
 
-	set_bit(SELECTIVE_SUSPEND, &tp->flags);
-
 out1:
 	return ret;
 }
@@ -3681,12 +3696,15 @@ static int rtl8152_resume(struct usb_interface *intf)
 	if (netif_running(tp->netdev) && tp->netdev->flags & IFF_UP) {
 		if (test_bit(SELECTIVE_SUSPEND, &tp->flags)) {
 			tp->rtl_ops.autosuspend_en(tp, false);
-			clear_bit(SELECTIVE_SUSPEND, &tp->flags);
 			napi_disable(&tp->napi);
 			set_bit(WORK_ENABLE, &tp->flags);
 			if (netif_carrier_ok(tp->netdev))
 				rtl_start_rx(tp);
 			napi_enable(&tp->napi);
+			clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+			smp_mb__after_atomic();
+			if (!list_empty(&tp->rx_done))
+				napi_schedule(&tp->napi);
 		} else {
 			tp->rtl_ops.up(tp);
 			netif_carrier_off(tp->netdev);