-----Original Message-----
> Date: Fri, 5 Oct 2018 20:56:47 +0100
> From: Ferruh Yigit <ferruh.yi...@intel.com>
> To: Jerin Jacob <jerin.ja...@caviumnetworks.com>, John McNamara
> <john.mcnam...@intel.com>, Marko Kovacevic <marko.kovace...@intel.com>
> CC: dev@dpdk.org, tho...@monjalon.net, arybche...@solarflare.com,
> olivier.m...@6wind.com, sta...@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/2] doc: clarify L3 Tx checksum prerequisite
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> Thunderbird/52.9.1
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> External Email
>
> 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: sta...@dpdk.org
> >
> > Signed-off-by: Jerin Jacob <jerin.ja...@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?
IMO, there will not be any confusion as mbuf.l2_len comes under
uint64_t tx_offload in struct rte_mbuf.
>
>
> > * **[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``.
> >
>
