[dpdk-stable] [PATCH 19.11] net/ixgbe: fix jumbo frame flag condition

[dpdk-stable] [PATCH 19.11] net/ixgbe: fix jumbo frame flag condition

[Steve Yang]

[ upstream commit 48554c7db7eaef9b7c69f7ad8dd60fe53e78fbde ]

The jumbo frame uses the 'RTE_ETHER_MAX_LEN' as boundary condition.
If 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 normalize the boundary condition with 'RTE_ETHER_MTU'
and overhead even though current overhead is 18.

Fixes: 59d0ecdbf0e1 ("ethdev: MTU accessors")
Fixes: 95a27b3ba5f5 ("net/ixgbe: enable jumbo frame for VF")
Cc: stable@dpdk.org

Acked-by: Jeff Guo <jia.guo@intel.com>

Signed-off-by: Steve Yang <stevex.yang@intel.com>
---
 drivers/net/ixgbe/ixgbe_ethdev.c | 2 +-
 drivers/net/ixgbe/ixgbe_ethdev.h | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index de528d242b..4821c203cc 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -5222,7 +5222,7 @@ ixgbe_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 	hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
 
 	/* switch to jumbo mode if needed */
-	if (frame_size > RTE_ETHER_MAX_LEN) {
+	if (frame_size > IXGBE_ETH_MAX_LEN) {
 		dev->data->dev_conf.rxmode.offloads |=
 			DEV_RX_OFFLOAD_JUMBO_FRAME;
 		hlreg0 |= IXGBE_HLREG0_JUMBOEN;
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index edb66f8258..e406b754e8 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -104,6 +104,9 @@
 /* The overhead from MTU to max frame size. */
 #define IXGBE_ETH_OVERHEAD (RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN)
 
+/* The max frame size with default MTU */
+#define IXGBE_ETH_MAX_LEN  (RTE_ETHER_MTU + IXGBE_ETH_OVERHEAD)
+
 /* bit of VXLAN tunnel type | 7 bits of zeros  | 8 bits of zeros*/
 #define IXGBE_FDIR_VXLAN_TUNNEL_TYPE    0x8000
 /* bit of NVGRE tunnel type | 7 bits of zeros  | 8 bits of zeros*/
-- 
2.17.1