[dpdk-dev] [PATCH] doc: add deprecation notice to fix ethdev API returning void

[Andrew Rybchenko <arybchenko@solarflare.com>]

void return value is bad for get API (like rte_eth_dev_info-get())
since caller does not know if the function does its job or not and
output value is filled in.

void return value is bad for state changing API (like
rte_eth_promiscuous_enable()) since caller should use get API
to understand if state is really changed.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 doc/guides/rel_notes/deprecation.rst | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 37b8592b6..79689f136 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -59,6 +59,20 @@ Deprecation Notices
   Target release for removal of the legacy API will be defined once most
   PMDs have switched to rte_flow.
 
+* ethdev: update API functions returning ``void`` to return ``int`` with
+  negative errno values to indicate various error conditions (e.g.
+  invalid port ID, unsupported operation, failed operation):
+
+  - ``rte_eth_dev_info_get``
+  - ``rte_eth_promiscuous_enable`` and ``rte_eth_promiscuous_disable``
+  - ``rte_eth_allmulticast_enable`` and ``rte_eth_allmulticast_disable``
+  - ``rte_eth_link_get`` and ``rte_eth_link_get_nowait``
+  - ``rte_eth_dev_stop``
+  - ``rte_eth_dev_close``
+  - ``rte_eth_xstats_reset``
+  - ``rte_eth_macaddr_get``
+  - ``rte_eth_dev_owner_delete``
+
 * cryptodev: support for using IV with all sizes is added, J0 still can
   be used but only when IV length in following structs ``rte_crypto_auth_xform``,
   ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
-- 
2.17.1