From 866b4f3e94a7568a1cb0018c061e19e120de6922 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 23 Mar 2006 11:07:27 -0800 Subject: [PATCH] [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 Signed-off-by: Jeff Garzik --- drivers/net/skge.c | 73 ++++++++++++++++++++++++---------------------- 1 file changed, 38 insertions(+), 35 deletions(-) diff --git a/drivers/net/skge.c b/drivers/net/skge.c index e15cbefcb6e..a261766bc05 100644 --- a/drivers/net/skge.c +++ b/drivers/net/skge.c @@ -2404,35 +2404,39 @@ static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev) return NETDEV_TX_OK; } -static inline void skge_tx_free(struct skge_hw *hw, struct skge_element *e) -{ - /* 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); +static void skge_tx_complete(struct skge_port *skge, struct skge_element *last) +{ + 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 @@ resubmit: 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) -- 2.32.0.93.g670b81a890