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Commit 992c9623 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
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skge: transmit locking improvements 



Don't need to lock when processing transmit complete unless queue fills.
Modeled after tg3.

Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 7e0038a4

drivers/net/skge.c

+18 −10
Original line number Diff line number Diff line
@@ -2621,6 +2621,7 @@ static int skge_down(struct net_device *dev) 


static inline int skge_avail(const struct skge_ring *ring)

{

	smp_mb();

	return ((ring->to_clean > ring->to_use) ? 0 : ring->count)

		+ (ring->to_clean - ring->to_use) - 1;

}
@@ -2709,6 +2710,8 @@ static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev) 
		       dev->name, e - skge->tx_ring.start, skb->len);



	skge->tx_ring.to_use = e->next;

	smp_wmb();



	if (skge_avail(&skge->tx_ring) <= TX_LOW_WATER) {

		pr_debug("%s: transmit queue full\n", dev->name);

		netif_stop_queue(dev);
@@ -2726,8 +2729,6 @@ static void skge_tx_free(struct skge_port *skge, struct skge_element *e, 
{

	struct pci_dev *pdev = skge->hw->pdev;



	BUG_ON(!e->skb);



	/* skb header vs. fragment */

	if (control & BMU_STF)

		pci_unmap_single(pdev, pci_unmap_addr(e, mapaddr),
@@ -2745,7 +2746,6 @@ static void skge_tx_free(struct skge_port *skge, struct skge_element *e, 


		dev_kfree_skb(e->skb);

	}

	e->skb = NULL;

}



/* Free all buffers in transmit ring */
@@ -3017,22 +3017,30 @@ static void skge_tx_done(struct net_device *dev) 


	skge_write8(skge->hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F);



	netif_tx_lock(dev);

	for (e = ring->to_clean; e != ring->to_use; e = e->next) {

		struct skge_tx_desc *td = e->desc;

		u32 control = ((const struct skge_tx_desc *) e->desc)->control;



		if (td->control & BMU_OWN)

		if (control & BMU_OWN)

			break;



		skge_tx_free(skge, e, td->control);

		skge_tx_free(skge, e, control);

	}

	skge->tx_ring.to_clean = e;



	if (skge_avail(&skge->tx_ring) > TX_LOW_WATER)

	/* Can run lockless until we need to synchronize to restart queue. */

	smp_mb();



	if (unlikely(netif_queue_stopped(dev) &&

		     skge_avail(&skge->tx_ring) > TX_LOW_WATER)) {

		netif_tx_lock(dev);

		if (unlikely(netif_queue_stopped(dev) &&

			     skge_avail(&skge->tx_ring) > TX_LOW_WATER)) {

			netif_wake_queue(dev);



		}

		netif_tx_unlock(dev);

	}

}



static int skge_poll(struct net_device *dev, int *budget)

{