net: usb: r8152: use irqsave() in USB's complete callback

The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/r8152.c

@@ -1252,6 +1252,7 @@ static void read_bulk_callback(struct urb *urb)
 	int status = urb->status;
 	struct rx_agg *agg;
 	struct r8152 *tp;
+	unsigned long flags;
 
 	agg = urb->context;
 	if (!agg)
@@ -1281,9 +1282,9 @@ static void read_bulk_callback(struct urb *urb)
 		if (urb->actual_length < ETH_ZLEN)
 			break;
 
-		spin_lock(&tp->rx_lock);
+		spin_lock_irqsave(&tp->rx_lock, flags);
 		list_add_tail(&agg->list, &tp->rx_done);
-		spin_unlock(&tp->rx_lock);
+		spin_unlock_irqrestore(&tp->rx_lock, flags);
 		napi_schedule(&tp->napi);
 		return;
 	case -ESHUTDOWN:
@@ -1311,6 +1312,7 @@ static void write_bulk_callback(struct urb *urb)
 	struct net_device *netdev;
 	struct tx_agg *agg;
 	struct r8152 *tp;
+	unsigned long flags;
 	int status = urb->status;
 
 	agg = urb->context;
@@ -1332,9 +1334,9 @@ static void write_bulk_callback(struct urb *urb)
 		stats->tx_bytes += agg->skb_len;
 	}
 
-	spin_lock(&tp->tx_lock);
+	spin_lock_irqsave(&tp->tx_lock, flags);
 	list_add_tail(&agg->list, &tp->tx_free);
-	spin_unlock(&tp->tx_lock);
+	spin_unlock_irqrestore(&tp->tx_lock, flags);
 
 	usb_autopm_put_interface_async(tp->intf);