ixgbe: properly return CHECKSUM_NONE, cleanup csum code

We were not returning CHECKSUM_NONE in a lot of cases which is
wrong. Move common exit points in this function and error code
up before the actual work in this function.

Signed-off-by: Ayyappan Veeraiyan <ayyappan.veeraiyan@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 22 insertions, 7 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index c814d9bfbca7..ee5ee10c918f 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -304,25 +304,40 @@ static void ixgbe_receive_skb(struct ixgbe_adapter *adapter,
         }
 }
 
+/**
+ * ixgbe_rx_checksum - indicate in skb if hw indicated a good cksum
+ * @adapter: address of board private structure
+ * @status_err: hardware indication of status of receive
+ * @skb: skb currently being received and modified
+ **/
 static inline void ixgbe_rx_checksum(struct ixgbe_adapter *adapter,
                                          u32 status_err,
                                          struct sk_buff *skb)
 {
         skb->ip_summed = CHECKSUM_NONE;
 
-        /* Ignore Checksum bit is set */
+        /* Ignore Checksum bit is set, or rx csum disabled */
         if ((status_err & IXGBE_RXD_STAT_IXSM) ||
-                     !(adapter->flags & IXGBE_FLAG_RX_CSUM_ENABLED))
+            !(adapter->flags & IXGBE_FLAG_RX_CSUM_ENABLED))
                 return;
-        /* TCP/UDP checksum error bit is set */
-        if (status_err & (IXGBE_RXDADV_ERR_TCPE | IXGBE_RXDADV_ERR_IPE)) {
-                /* let the stack verify checksum errors */
+
+        /* if IP and error */
+        if ((status_err & IXGBE_RXD_STAT_IPCS) &&
+            (status_err & IXGBE_RXDADV_ERR_IPE)) {
                 adapter->hw_csum_rx_error++;
                 return;
         }
+
+        if (!(status_err & IXGBE_RXD_STAT_L4CS))
+                return;
+
+        if (status_err & IXGBE_RXDADV_ERR_TCPE) {
+                adapter->hw_csum_rx_error++;
+                return;
+        }
+
         /* It must be a TCP or UDP packet with a valid checksum */
-        if (status_err & (IXGBE_RXD_STAT_L4CS | IXGBE_RXD_STAT_UDPCS))
-                skb->ip_summed = CHECKSUM_UNNECESSARY;
+        skb->ip_summed = CHECKSUM_UNNECESSARY;
         adapter->hw_csum_rx_good++;
 }