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>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index ea17319624aa..468356d124ea 100644
--- 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;