Re: [dpdk-dev] [PATCH 1/2] doc: clarify L3 Tx checksum prerequisite

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/5/2018 5:46 AM, Jerin Jacob wrote:
> Based on PKT_TX_IP_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@dpdk.org
> 
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> ---
> 
> See PKT_TX_IP_CKSUM at
> https://git.dpdk.org/dpdk/tree/lib/librte_mbuf/rte_mbuf.h#n283
> 
> ---
>  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 b085bda86..e726a6bb8 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -562,6 +562,7 @@ Supports L3 checksum offload.
>  * **[uses]     rte_eth_txconf,rte_eth_txmode**: ``offloads:DEV_TX_OFFLOAD_IPV4_CKSUM``.
>  * **[uses]     mbuf**: ``mbuf.ol_flags:PKT_TX_IP_CKSUM``,
>    ``mbuf.ol_flags:PKT_TX_IPV4`` | ``PKT_TX_IPV6``.
> +* **[uses]     mbuf**: ``mbuf.l2_len``, ``mbuf.l3_len``.

Thanks this was missing.

``mbuf.l2_len``, ``mbuf.l3_len`` are required for TX CKSUM offload, in
documentation there is no distinction for Rx or Tx, do you think does it worth
to clarify PMD `uses` these values for Tx cksum offload only?


>  * **[provides] mbuf**: ``mbuf.ol_flags:PKT_RX_IP_CKSUM_UNKNOWN`` |
>    ``PKT_RX_IP_CKSUM_BAD`` | ``PKT_RX_IP_CKSUM_GOOD`` |
>    ``PKT_RX_IP_CKSUM_NONE``.
>