ks8842: Do the TX timeout work in workqueue context.

Currently all code that needs to be run at TX timeout is done in the
calling context, where bottom halves are disabled. Some of the code
blocks, so it needs to be done in a different context. This patch
adds in a work struct which is scheduled at TX timeout. Then the
timeout code is executed within work queue context.

Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ks8842.c

@@ -119,6 +119,8 @@ struct ks8842_adapter {
 	int		irq;
 	struct tasklet_struct	tasklet;
 	spinlock_t	lock; /* spinlock to be interrupt safe */
+	struct work_struct timeout_work;
+	struct net_device *netdev;
 };
 
 static inline void ks8842_select_bank(struct ks8842_adapter *adapter, u16 bank)
@@ -553,6 +555,8 @@ static int ks8842_close(struct net_device *netdev)
 
 	netdev_dbg(netdev, "%s - entry\n", __func__);
 
+	cancel_work_sync(&adapter->timeout_work);
+
 	/* free the irq */
 	free_irq(adapter->irq, netdev);
 
@@ -595,9 +599,11 @@ static int ks8842_set_mac(struct net_device *netdev, void *p)
 	return 0;
 }
 
-static void ks8842_tx_timeout(struct net_device *netdev)
+static void ks8842_tx_timeout_work(struct work_struct *work)
 {
-	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_adapter *adapter =
+		container_of(work, struct ks8842_adapter, timeout_work);
+	struct net_device *netdev = adapter->netdev;
 	unsigned long flags;
 
 	netdev_dbg(netdev, "%s: entry\n", __func__);
@@ -606,6 +612,9 @@ static void ks8842_tx_timeout(struct net_device *netdev)
 	/* disable interrupts */
 	ks8842_write16(adapter, 18, 0, REG_IER);
 	ks8842_write16(adapter, 18, 0xFFFF, REG_ISR);
+
+	netif_stop_queue(netdev);
+
 	spin_unlock_irqrestore(&adapter->lock, flags);
 
 	ks8842_reset_hw(adapter);
@@ -615,6 +624,15 @@ static void ks8842_tx_timeout(struct net_device *netdev)
 	ks8842_update_link_status(netdev, adapter);
 }
 
+static void ks8842_tx_timeout(struct net_device *netdev)
+{
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+
+	netdev_dbg(netdev, "%s: entry\n", __func__);
+
+	schedule_work(&adapter->timeout_work);
+}
+
 static const struct net_device_ops ks8842_netdev_ops = {
 	.ndo_open		= ks8842_open,
 	.ndo_stop		= ks8842_close,
@@ -649,6 +667,8 @@ static int __devinit ks8842_probe(struct platform_device *pdev)
 	SET_NETDEV_DEV(netdev, &pdev->dev);
 
 	adapter = netdev_priv(netdev);
+	adapter->netdev = netdev;
+	INIT_WORK(&adapter->timeout_work, ks8842_tx_timeout_work);
 	adapter->hw_addr = ioremap(iomem->start, resource_size(iomem));
 	if (!adapter->hw_addr)
 		goto err_ioremap;