[PATCH] skge: dont free skb until multi-part transmit complete
Don't free transmit buffers until the whole set of transmit descriptors
has been marked as done. Otherwise, we risk freeing a skb before the
whole transmit is done.
This changes the transmit completion handling from incremental to a
two pass algorithm. First pass scans and records the start of the last
done descriptor, second cleans up until that point.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index e15cbef..a261766 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -2404,35 +2404,39 @@
return NETDEV_TX_OK;
}
-static inline void skge_tx_free(struct skge_hw *hw, struct skge_element *e)
+static void skge_tx_complete(struct skge_port *skge, struct skge_element *last)
{
- /* This ring element can be skb or fragment */
- if (e->skb) {
- pci_unmap_single(hw->pdev,
- pci_unmap_addr(e, mapaddr),
- pci_unmap_len(e, maplen),
- PCI_DMA_TODEVICE);
- dev_kfree_skb(e->skb);
+ struct pci_dev *pdev = skge->hw->pdev;
+ struct skge_element *e;
+
+ for (e = skge->tx_ring.to_clean; e != last; e = e->next) {
+ struct sk_buff *skb = e->skb;
+ int i;
+
e->skb = NULL;
- } else {
- pci_unmap_page(hw->pdev,
- pci_unmap_addr(e, mapaddr),
- pci_unmap_len(e, maplen),
- PCI_DMA_TODEVICE);
+ pci_unmap_single(pdev, pci_unmap_addr(e, mapaddr),
+ skb_headlen(skb), PCI_DMA_TODEVICE);
+ ++skge->tx_avail;
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ e = e->next;
+ pci_unmap_page(pdev, pci_unmap_addr(e, mapaddr),
+ skb_shinfo(skb)->frags[i].size,
+ PCI_DMA_TODEVICE);
+ ++skge->tx_avail;
+ }
+
+ dev_kfree_skb(skb);
}
+ skge->tx_ring.to_clean = e;
}
static void skge_tx_clean(struct skge_port *skge)
{
- struct skge_ring *ring = &skge->tx_ring;
- struct skge_element *e;
spin_lock_bh(&skge->tx_lock);
- for (e = ring->to_clean; e != ring->to_use; e = e->next) {
- ++skge->tx_avail;
- skge_tx_free(skge->hw, e);
- }
- ring->to_clean = e;
+ skge_tx_complete(skge, skge->tx_ring.to_use);
+ netif_wake_queue(skge->netdev);
spin_unlock_bh(&skge->tx_lock);
}
@@ -2662,27 +2666,26 @@
static void skge_tx_done(struct skge_port *skge)
{
struct skge_ring *ring = &skge->tx_ring;
- struct skge_element *e;
+ struct skge_element *e, *last;
spin_lock(&skge->tx_lock);
- for (e = ring->to_clean; prefetch(e->next), e != ring->to_use; e = e->next) {
+ last = ring->to_clean;
+ for (e = ring->to_clean; e != ring->to_use; e = e->next) {
struct skge_tx_desc *td = e->desc;
- u32 control;
- rmb();
- control = td->control;
- if (control & BMU_OWN)
+ if (td->control & BMU_OWN)
break;
- if (unlikely(netif_msg_tx_done(skge)))
- printk(KERN_DEBUG PFX "%s: tx done slot %td status 0x%x\n",
- skge->netdev->name, e - ring->start, td->status);
-
- skge_tx_free(skge->hw, e);
- e->skb = NULL;
- ++skge->tx_avail;
+ if (td->control & BMU_EOF) {
+ last = e->next;
+ if (unlikely(netif_msg_tx_done(skge)))
+ printk(KERN_DEBUG PFX "%s: tx done slot %td\n",
+ skge->netdev->name, e - ring->start);
+ }
}
- ring->to_clean = e;
+
+ skge_tx_complete(skge, last);
+
skge_write8(skge->hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F);
if (skge->tx_avail > MAX_SKB_FRAGS + 1)