net/hns3: fix jumbo frame flag condition for MTU set

[ upstream commit 3ec35c6 ]

The jumbo frame uses the 'RTE_ETHER_MAX_LEN' as boundary condition,
but the Ether overhead is larger than 18 when it supports dual VLAN tags.
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 'HSN3_DEFAULT_FRAME_LEN',
that perhaps impacts the cases of the jumbo frame related.

Fixes: 1f5ca0b ("net/hns3: support some device operations")
Fixes: a5475d6 ("net/hns3: support VF")

Signed-off-by: Steve Yang <stevex.yang@intel.com>
Acked-by: Lijun Ou <oulijun@huawei.com>

drivers/net/hns3/hns3_ethdev.c

@@ -2420,7 +2420,7 @@ hns3_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 	}
 
 	rte_spinlock_lock(&hw->lock);
-	is_jumbo_frame = frame_size > RTE_ETHER_MAX_LEN ? true : false;
+	is_jumbo_frame = frame_size > HNS3_DEFAULT_FRAME_LEN ? true : false;
 	frame_size = RTE_MAX(frame_size, HNS3_DEFAULT_FRAME_LEN);
 
 	/*

drivers/net/hns3/hns3_ethdev_vf.c

@@ -801,7 +801,7 @@ hns3vf_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 		rte_spinlock_unlock(&hw->lock);
 		return ret;
 	}
-	if (frame_size > RTE_ETHER_MAX_LEN)
+	if (mtu > RTE_ETHER_MTU)
 		dev->data->dev_conf.rxmode.offloads |=
 						DEV_RX_OFFLOAD_JUMBO_FRAME;
 	else