igb: fix unmap length bug

driver was mixing NET_IP_ALIGN count bytes in map/unmap calls
unevenly. Only map the bytes that the hardware might dma into

also fix unmap related bug where ->dma was not being cleared
after unmap

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index ea17319..468356d 100644 (file)
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -4549,11 +4549,12 @@ static bool igb_clean_rx_irq_adv(struct igb_ring *rx_ring,
                cleaned = true;
                cleaned_count++;
 
+               /* this is the fast path for the non-packet split case */
                if (!adapter->rx_ps_hdr_size) {
                        pci_unmap_single(pdev, buffer_info->dma,
-                                        adapter->rx_buffer_len +
-                                          NET_IP_ALIGN,
+                                        adapter->rx_buffer_len,
                                         PCI_DMA_FROMDEVICE);
+                       buffer_info->dma = 0;
                        skb_put(skb, length);
                        goto send_up;
                }
@@ -4570,8 +4571,9 @@ static bool igb_clean_rx_irq_adv(struct igb_ring *rx_ring,
 
                if (!skb_shinfo(skb)->nr_frags) {
                        pci_unmap_single(pdev, buffer_info->dma,
-                                        adapter->rx_ps_hdr_size + NET_IP_ALIGN,
+                                        adapter->rx_ps_hdr_size,
                                         PCI_DMA_FROMDEVICE);
+                       buffer_info->dma = 0;
                        skb_put(skb, hlen);
                }
 
@@ -4713,7 +4715,6 @@ static void igb_alloc_rx_buffers_adv(struct igb_ring *rx_ring,
                bufsz = adapter->rx_ps_hdr_size;
        else
                bufsz = adapter->rx_buffer_len;
-       bufsz += NET_IP_ALIGN;
 
        while (cleaned_count--) {
                rx_desc = E1000_RX_DESC_ADV(*rx_ring, i);
@@ -4737,7 +4738,7 @@ static void igb_alloc_rx_buffers_adv(struct igb_ring *rx_ring,
                }
 
                if (!buffer_info->skb) {
-                       skb = netdev_alloc_skb(netdev, bufsz);
+                       skb = netdev_alloc_skb(netdev, bufsz + NET_IP_ALIGN);
                        if (!skb) {
                                adapter->alloc_rx_buff_failed++;
                                goto no_buffers;