doc: announce ABI change for Tx offload

This is an ABI change notice for DPDK 17.08 in ethdev
about changes in rte_eth_txmode structure.

Currently Tx offloads are enabled by default, and can be disabled
using ETH_TXQ_FLAGS_NO* flags. This behaviour is not consistent with
the Rx side where the Rx offloads are disabled by default and enabled
according to bit field in rte_eth_rxmode structure.

The proposal is to disable the Tx offloads by default, and provide
a way for the application to enable them in rte_eth_txmode structure.
Besides of making the Tx configuration API more consistent for
applications, PMDs will be able to provide a better out of the
box performance.
Finally, as part of the work, the ETH_TXQ_FLAGS_NO* will
be superseded as well.

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 67324a2..02f64ee 100644 (file)
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -75,6 +75,13 @@ Deprecation Notices
   PKT_RX_QINQ_STRIPPED, that are better described. The old flags and
   their behavior will be kept until 17.02 and will be removed in 17.05.
 
+* ethdev: Tx offloads will no longer be enabled by default in 17.08.
+  Instead, the ``rte_eth_txmode`` structure will be extended with
+  bit field to enable each Tx offload.
+  Besides of making the Rx/Tx configuration API more consistent for the
+  application, PMDs will be able to provide a better out of the box performance.
+  As part of the work, ``ETH_TXQ_FLAGS_NO*`` will be superseded as well.
+
 * ethdev: the legacy filter API, including
   ``rte_eth_dev_filter_supported()``, ``rte_eth_dev_filter_ctrl()`` as well
   as filter types MACVLAN, ETHERTYPE, FLEXIBLE, SYN, NTUPLE, TUNNEL, FDIR,