Commit 41c1ef97 authored Feb 05, 2020 by Harini Katakam Committed by David S. Miller Feb 05, 2020

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: 1629dd4f ("cadence: Add LSO support.")
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 38f88c45

drivers/net/ethernet/cadence/macb_main.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -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.
		*/

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