From 1b7719c4559dc1522065d4cfd033f8bb8f969159 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 19 Mar 2009 01:12:50 +0000 Subject: [PATCH] e1000e: fix dma error handling issues There were a few issues I noticed in e1000e. These include a double free of the skb if mapping fails, and the fact that context descriptors appear to be left in the descriptor ring after the failure. Signed-off-by: Alexander Duyck Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/e1000e/netdev.c | 76 +++++++++++++++++++-------------------------- 1 file changed, 32 insertions(+), 44 deletions(-) diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c index 402d2dd..da876d5 100644 --- a/drivers/net/e1000e/netdev.c +++ b/drivers/net/e1000e/netdev.c @@ -574,6 +574,7 @@ static void e1000_put_txbuf(struct e1000_adapter *adapter, dev_kfree_skb_any(buffer_info->skb); buffer_info->skb = NULL; } + buffer_info->time_stamp = 0; } static void e1000_print_tx_hang(struct e1000_adapter *adapter) @@ -678,17 +679,10 @@ static bool e1000_clean_tx_irq(struct e1000_adapter *adapter) } if (adapter->detect_tx_hung) { - /* - * Detect a transmit hang in hardware, this serializes the - * check with the clearing of time_stamp and movement of i - */ + /* Detect a transmit hang in hardware, this serializes the + * check with the clearing of time_stamp and movement of i */ adapter->detect_tx_hung = 0; - /* - * read barrier to make sure that the ->dma member and time - * stamp are updated fully - */ - smp_rmb(); - if (tx_ring->buffer_info[eop].dma && + if (tx_ring->buffer_info[eop].time_stamp && time_after(jiffies, tx_ring->buffer_info[eop].time_stamp + (adapter->tx_timeout_factor * HZ)) && !(er32(STATUS) & E1000_STATUS_TXOFF)) { @@ -3824,39 +3818,41 @@ static int e1000_tx_map(struct e1000_adapter *adapter, unsigned int mss) { struct e1000_ring *tx_ring = adapter->tx_ring; + struct e1000_buffer *buffer_info; unsigned int len = skb_headlen(skb); unsigned int offset, size, count = 0, i; unsigned int f; - dma_addr_t map; + dma_addr_t *map; i = tx_ring->next_to_use; if (skb_dma_map(&adapter->pdev->dev, skb, DMA_TO_DEVICE)) { dev_err(&adapter->pdev->dev, "TX DMA map failed\n"); adapter->tx_dma_failed++; - dev_kfree_skb(skb); - return -2; + return 0; } - map = skb_shinfo(skb)->dma_maps[0]; + map = skb_shinfo(skb)->dma_maps; offset = 0; while (len) { - struct e1000_buffer *buffer_info = &tx_ring->buffer_info[i]; + buffer_info = &tx_ring->buffer_info[i]; size = min(len, max_per_txd); buffer_info->length = size; - /* set time_stamp *before* dma to help avoid a possible race */ buffer_info->time_stamp = jiffies; - buffer_info->dma = map + offset; buffer_info->next_to_watch = i; + buffer_info->dma = map[0] + offset; + count++; len -= size; offset += size; - count++; - i++; - if (i == tx_ring->count) - i = 0; + + if (len) { + i++; + if (i == tx_ring->count) + i = 0; + } } for (f = 0; f < nr_frags; f++) { @@ -3864,37 +3860,29 @@ static int e1000_tx_map(struct e1000_adapter *adapter, frag = &skb_shinfo(skb)->frags[f]; len = frag->size; - map = skb_shinfo(skb)->dma_maps[f + 1]; offset = 0; while (len) { - struct e1000_buffer *buffer_info; + i++; + if (i == tx_ring->count) + i = 0; + buffer_info = &tx_ring->buffer_info[i]; size = min(len, max_per_txd); buffer_info->length = size; buffer_info->time_stamp = jiffies; - buffer_info->dma = map + offset; buffer_info->next_to_watch = i; + buffer_info->dma = map[f + 1] + offset; len -= size; offset += size; count++; - - i++; - if (i == tx_ring->count) - i = 0; } } - if (i == 0) - i = tx_ring->count - 1; - else - i--; - tx_ring->buffer_info[i].skb = skb; tx_ring->buffer_info[first].next_to_watch = i; - smp_wmb(); return count; } @@ -4145,20 +4133,20 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev) if (skb->protocol == htons(ETH_P_IP)) tx_flags |= E1000_TX_FLAGS_IPV4; + /* if count is 0 then mapping error has occured */ count = e1000_tx_map(adapter, skb, first, max_per_txd, nr_frags, mss); - if (count < 0) { - /* handle pci_map_single() error in e1000_tx_map */ + if (count) { + e1000_tx_queue(adapter, tx_flags, count); + netdev->trans_start = jiffies; + /* Make sure there is space in the ring for the next send. */ + e1000_maybe_stop_tx(netdev, MAX_SKB_FRAGS + 2); + + } else { dev_kfree_skb_any(skb); - return NETDEV_TX_OK; + tx_ring->buffer_info[first].time_stamp = 0; + tx_ring->next_to_use = first; } - e1000_tx_queue(adapter, tx_flags, count); - - netdev->trans_start = jiffies; - - /* Make sure there is space in the ring for the next send. */ - e1000_maybe_stop_tx(netdev, MAX_SKB_FRAGS + 2); - return NETDEV_TX_OK; } -- 2.7.4