net: dsa: Fix Marvell Egress Trailer check

The Marvell Egress rx trailer check must be fixed to
correctly detect bad bits in the third byte of the
Eggress trailer as described in the Table 28 of the
88E6060 datasheet.
The current code incorrectly omits to check the third
byte and checks the fourth byte twice.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
index d25efc93d8f120739c83c3998e77d5e9dd3cfc45..b6ca0890d0188550f83d5d79939acb333778cb20 100644 (file)
--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -78,7 +78,7 @@ static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 
        trailer = skb_tail_pointer(skb) - 4;
        if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
-           (trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00)
+           (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00)
                goto out_drop;
 
        source_port = trailer[1] & 7;