net/ena: fix checksum flag for L4

[ upstream commit b2d2f1c ]

Some HW may invalidly set checksum error bit for the valid L4 checksum.
To avoid drop of the packets in that situation, do not indicate bad
checksum for L4 Rx csum offloads. Instead, set it as unknown, so the
application will re-verify this value.

The statistics counters will still work as previously.

Fixes: 0581705 ("net/ena: fix indication of bad L4 Rx checksums")

Signed-off-by: Michal Krawczyk <mk@semihalf.com>

drivers/net/ena/ena_ethdev.c

@@ -337,7 +337,13 @@ static inline void ena_rx_mbuf_prepare(struct rte_mbuf *mbuf,
 		ol_flags |= PKT_RX_L4_CKSUM_UNKNOWN;
 	else
 		if (unlikely(ena_rx_ctx->l4_csum_err))
-			ol_flags |= PKT_RX_L4_CKSUM_BAD;
+			/*
+			 * For the L4 Rx checksum offload the HW may indicate
+			 * bad checksum although it's valid. Because of that,
+			 * we're setting the UNKNOWN flag to let the app
+			 * re-verify the checksum.
+			 */
+			ol_flags |= PKT_RX_L4_CKSUM_UNKNOWN;
 		else
 			ol_flags |= PKT_RX_L4_CKSUM_GOOD;