igb: update tx DMA mapping error handling

This updates the tx DMA mapping error handling code to
resemble e1000e/ixgbe.

Signed-off-by: Nicholas Nunley <nicholasx.d.nunley@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 5 deletions

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index ab7c5e97ed02..f588e49c65f1 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -3647,14 +3647,12 @@ dma_error:
         buffer_info->length = 0;
         buffer_info->next_to_watch = 0;
         buffer_info->mapped_as_page = false;
-        count--;
 
         /* clear timestamp and dma mappings for remaining portion of packet */
-        while (count >= 0) {
-                count--;
+        while (count--) {
+                if (i == 0)
+                        i = tx_ring->count;
                 i--;
-                if (i < 0)
-                        i += tx_ring->count;
                 buffer_info = &tx_ring->buffer_info[i];
                 igb_unmap_and_free_tx_resource(tx_ring, buffer_info);
         }