[dpdk-stable] [dpdk-dev] [PATCH 2/2] doc: clarify L4 Tx checksum prerequisite

[Jerin Jacob]

Based on PKT_TX_[TCP|UDP|SCTP]_CKSUM definition the user needs
to fill l2_len and l3_len mbuf fields before issuing HW Tx
checksum request.

Fixes: dad1ec72a377 ("doc: document NIC features")
Cc: stable at dpdk.org

Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
---

See PKT_TX_TCP_CKSUM defintion at
https://git.dpdk.org/dpdk/tree/lib/librte_mbuf/rte_mbuf.h#n269

---
 doc/guides/nics/features.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
index e726a6bb8..c39fb0074 100644
--- a/doc/guides/nics/features.rst
+++ b/doc/guides/nics/features.rst
@@ -582,6 +582,7 @@ Supports L4 checksum offload.
 * **[uses]     mbuf**: ``mbuf.ol_flags:PKT_TX_IPV4`` | ``PKT_TX_IPV6``,
   ``mbuf.ol_flags:PKT_TX_L4_NO_CKSUM`` | ``PKT_TX_TCP_CKSUM`` |
   ``PKT_TX_SCTP_CKSUM`` | ``PKT_TX_UDP_CKSUM``.
+* **[uses]     mbuf**: ``mbuf.l2_len``, ``mbuf.l3_len``.
 * **[provides] mbuf**: ``mbuf.ol_flags:PKT_RX_L4_CKSUM_UNKNOWN`` |
   ``PKT_RX_L4_CKSUM_BAD`` | ``PKT_RX_L4_CKSUM_GOOD`` |
   ``PKT_RX_L4_CKSUM_NONE``.
-- 
2.19.0