[PATCH] net/ice: fix assumption about tag placement order

[Bruce Richardson]

The specific placement of outer/inner VLAN tags in E810 and related NICs
is configurable. Therefore, remove the assumption that if the L2Tag2
field is filled in, that the L2Tag1 must also be. Instead, check the
existing mbuf VLAN flags, and move tags and set flags as appropriate.
This fixes an issue where, with QinQ packets with different Tag ethtypes
(0x88a8 vs 0x8100), we get an mbuf reporting two valid tags, but only
having had one tag stripped.

Fixes: e0dcf94a0d7f ("net/ice: support VLAN ops")
Cc: stable at dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/intel/ice/ice_rxtx.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/intel/ice/ice_rxtx.c b/drivers/net/intel/ice/ice_rxtx.c
index da508592aa..f965aab6ee 100644
--- a/drivers/net/intel/ice/ice_rxtx.c
+++ b/drivers/net/intel/ice/ice_rxtx.c
@@ -1835,9 +1835,13 @@ ice_rxd_to_vlan_tci(struct rte_mbuf *mb, volatile union ci_rx_flex_desc *rxdp)
 #ifndef RTE_NET_INTEL_USE_16BYTE_DESC
 	if (rte_le_to_cpu_16(rxdp->wb.status_error1) &
 	    (1 << ICE_RX_FLEX_DESC_STATUS1_L2TAG2P_S)) {
-		mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED | RTE_MBUF_F_RX_QINQ |
-				RTE_MBUF_F_RX_VLAN_STRIPPED | RTE_MBUF_F_RX_VLAN;
-		mb->vlan_tci_outer = mb->vlan_tci;
+		if ((mb->ol_flags & RTE_MBUF_F_RX_VLAN_STRIPPED) == 0) {
+			mb->ol_flags |= RTE_MBUF_F_RX_VLAN | RTE_MBUF_F_RX_VLAN_STRIPPED;
+		} else {
+			/* if two tags, move Tag1 to outer tag field */
+			mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED | RTE_MBUF_F_RX_QINQ;
+			mb->vlan_tci_outer = mb->vlan_tci;
+		}
 		mb->vlan_tci = rte_le_to_cpu_16(rxdp->wb.l2tag2_2nd);
 		PMD_RX_LOG(DEBUG, "Descriptor l2tag2_1: %u, l2tag2_2: %u",
 			   rte_le_to_cpu_16(rxdp->wb.l2tag2_1st),
-- 
2.48.1