net/sfc: fix jumbo frame flag condition for MTU set

[ upstream commit 7910fd2 ]

The jumbo frame uses the 'RTE_ETHER_MAX_LEN' as boundary condition,
but the Ether overhead is larger than 18 when it supports VLAN tag.
That will cause the jumbo flag rx offload is wrong when MTU size is
'RTE_ETHER_MTU'.

This fix will change the boundary condition with 'RTE_ETHER_MTU',
that perhaps impacts the cases of the jumbo frame related.

Fixes: ff6a119 ("net/sfc: convert to new Rx offload API")

Signed-off-by: Steve Yang <stevex.yang@intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

drivers/net/sfc/sfc_ethdev.c

@@ -984,7 +984,7 @@ sfc_dev_set_mtu(struct rte_eth_dev *dev, uint16_t mtu)
 	 * The driver does not use it, but other PMDs update jumbo frame
 	 * flag and max_rx_pkt_len when MTU is set.
 	 */
-	if (mtu > RTE_ETHER_MAX_LEN) {
+	if (mtu > RTE_ETHER_MTU) {
 		struct rte_eth_rxmode *rxmode = &dev->data->dev_conf.rxmode;
 		rxmode->offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
 	}