net: macb: Remove unnecessary alignment check for TSO

The IP TSO implementation does NOT require the length to be a
multiple of 8. That is only a requirement for UFO as per IP
documentation. Hence, exit macb_features_check function in the
beginning if the protocol is not UDP. Only when it is UDP,
proceed further to the alignment checks. Update comments to
reflect the same. Also remove dead code checking for protocol
TCP when calculating header length.

Fixes: ea218d5da8cd ("cadence: Add LSO support.")
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 7a2fe63d1136877b1ab0fad1297c0b2e3259b107..11311923e1662b9684c7cce347c313181fc54649 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1791,16 +1791,14 @@ static netdev_features_t macb_features_check(struct sk_buff *skb,
 
        /* Validate LSO compatibility */
 
-       /* there is only one buffer */
-       if (!skb_is_nonlinear(skb))
+       /* there is only one buffer or protocol is not UDP */
+       if (!skb_is_nonlinear(skb) || (ip_hdr(skb)->protocol != IPPROTO_UDP))
                return features;
 
        /* length of header */
        hdrlen = skb_transport_offset(skb);
-       if (ip_hdr(skb)->protocol == IPPROTO_TCP)
-               hdrlen += tcp_hdrlen(skb);
 
-       /* For LSO:
+       /* For UFO only:
         * When software supplies two or more payload buffers all payload buffers
         * apart from the last must be a multiple of 8 bytes in size.
         */