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author | Alexander Kochetkov <al.kochet@gmail.com> | 2017-12-15 20:20:06 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-12-19 13:24:23 -0500 |
commit | e688822d035b494071ecbadcccbd6f3325fb0f59 (patch) | |
tree | ff923bd3c48d2f90919f102f76b99ef7272b5974 /drivers/net/ethernet/arc | |
parent | 7352e252b5bf40d59342494a70354a2d436fd0cd (diff) | |
download | linux-e688822d035b494071ecbadcccbd6f3325fb0f59.tar.gz linux-e688822d035b494071ecbadcccbd6f3325fb0f59.tar.xz |
net: arc_emac: fix arc_emac_rx() error paths
arc_emac_rx() has some issues found by code review.
In case netdev_alloc_skb_ip_align() or dma_map_single() failure
rx fifo entry will not be returned to EMAC.
In case dma_map_single() failure previously allocated skb became
lost to driver. At the same time address of newly allocated skb
will not be provided to EMAC.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/arc')
-rw-r--r-- | drivers/net/ethernet/arc/emac_main.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c index 3241af1ce718..5b422be56165 100644 --- a/drivers/net/ethernet/arc/emac_main.c +++ b/drivers/net/ethernet/arc/emac_main.c @@ -210,39 +210,48 @@ static int arc_emac_rx(struct net_device *ndev, int budget) continue; } - pktlen = info & LEN_MASK; - stats->rx_packets++; - stats->rx_bytes += pktlen; - skb = rx_buff->skb; - skb_put(skb, pktlen); - skb->dev = ndev; - skb->protocol = eth_type_trans(skb, ndev); - - dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr), - dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE); - - /* Prepare the BD for next cycle */ - rx_buff->skb = netdev_alloc_skb_ip_align(ndev, - EMAC_BUFFER_SIZE); - if (unlikely(!rx_buff->skb)) { + /* Prepare the BD for next cycle. netif_receive_skb() + * only if new skb was allocated and mapped to avoid holes + * in the RX fifo. + */ + skb = netdev_alloc_skb_ip_align(ndev, EMAC_BUFFER_SIZE); + if (unlikely(!skb)) { + if (net_ratelimit()) + netdev_err(ndev, "cannot allocate skb\n"); + /* Return ownership to EMAC */ + rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE); stats->rx_errors++; - /* Because receive_skb is below, increment rx_dropped */ stats->rx_dropped++; continue; } - /* receive_skb only if new skb was allocated to avoid holes */ - netif_receive_skb(skb); - - addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data, + addr = dma_map_single(&ndev->dev, (void *)skb->data, EMAC_BUFFER_SIZE, DMA_FROM_DEVICE); if (dma_mapping_error(&ndev->dev, addr)) { if (net_ratelimit()) - netdev_err(ndev, "cannot dma map\n"); - dev_kfree_skb(rx_buff->skb); + netdev_err(ndev, "cannot map dma buffer\n"); + dev_kfree_skb(skb); + /* Return ownership to EMAC */ + rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE); stats->rx_errors++; + stats->rx_dropped++; continue; } + + /* unmap previosly mapped skb */ + dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr), + dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE); + + pktlen = info & LEN_MASK; + stats->rx_packets++; + stats->rx_bytes += pktlen; + skb_put(rx_buff->skb, pktlen); + rx_buff->skb->dev = ndev; + rx_buff->skb->protocol = eth_type_trans(rx_buff->skb, ndev); + + netif_receive_skb(rx_buff->skb); + + rx_buff->skb = skb; dma_unmap_addr_set(rx_buff, addr, addr); dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE); |