[dpdk-dev] [PATCH] net/i40e: fix dropping packets with Ethertype 0x88A8

[Beilei Xing <beilei.xing@intel.com>]

Refer to FW default setting, Ethertype 0x88A8 is treated as S-TAG,
packects with S-TAG should be received in Port Virtualizer mode,
but Port Virtual mode is not initialized in DPDK. So X710 will
packets with Ethertype 0x88A8.
This patch fixes this issue by turning off S-TAG identification.

Fixes: 4861cde46116 ("i40e: new poll mode driver")

Signed-off-by: Beilei Xing <beilei.xing@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index d0aeb70..55c4887 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -932,6 +932,9 @@ config_floating_veb(struct rte_eth_dev *dev)
 	}
 }
 
+#define I40E_L2_TAGS_S_TAG_SHIFT 1
+#define I40E_L2_TAGS_S_TAG_MASK I40E_MASK(0x1, I40E_L2_TAGS_S_TAG_SHIFT)
+
 static int
 eth_i40e_dev_init(struct rte_eth_dev *dev)
 {
@@ -1120,6 +1123,13 @@ eth_i40e_dev_init(struct rte_eth_dev *dev)
 	/* Disable double vlan by default */
 	i40e_vsi_config_double_vlan(vsi, FALSE);
 
+	/* Disable S-TAG identification by default */
+	ret = I40E_READ_REG(hw, I40E_PRT_L2TAGSEN);
+	if (ret & I40E_L2_TAGS_S_TAG_MASK) {
+		ret &= ~I40E_L2_TAGS_S_TAG_MASK;
+		I40E_WRITE_REG(hw, I40E_PRT_L2TAGSEN, ret);
+	}
+
 	if (!vsi->max_macaddrs)
 		len = ETHER_ADDR_LEN;
 	else
-- 
2.5.0