[dpdk-dev] [PATCH] net/sfc: discard last seen VLAN TCI if Tx packet is dropped

[Andrew Rybchenko <arybchenko@solarflare.com>]

From: Ivan Malov <ivan.malov@oktetlabs.ru>

Early processing of a packet on transmit may change last seen
VLAN TCI in the queue context. If such a packet is eventually
dropped, last seen VLAN TCI must be set to its previous value.

Fixes: 7fd636815a43 ("net/sfc: support VLAN offload on transmit path")
Cc: stable@dpdk.org

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 drivers/net/sfc/sfc_tx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index cce823954..aa73d2642 100644
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -712,6 +712,7 @@ sfc_efx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 	for (pkts_sent = 0, pktp = &tx_pkts[0];
 	     (pkts_sent < nb_pkts) && (fill_level <= soft_max_fill);
 	     pkts_sent++, pktp++) {
+		uint16_t		hw_vlan_tci_prev = txq->hw_vlan_tci;
 		struct rte_mbuf		*m_seg = *pktp;
 		size_t			pkt_len = m_seg->pkt_len;
 		unsigned int		pkt_descs = 0;
@@ -750,6 +751,7 @@ sfc_efx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 				 * mbuf shouldn't be orphaned
 				 */
 				pend -= pkt_descs;
+				txq->hw_vlan_tci = hw_vlan_tci_prev;
 
 				rte_pktmbuf_free(*pktp);
 
@@ -819,10 +821,12 @@ sfc_efx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 				fill_level = added - txq->completed;
 				if (fill_level > hard_max_fill) {
 					pend -= pkt_descs;
+					txq->hw_vlan_tci = hw_vlan_tci_prev;
 					break;
 				}
 			} else {
 				pend -= pkt_descs;
+				txq->hw_vlan_tci = hw_vlan_tci_prev;
 				break;
 			}
 		}
-- 
2.17.1