doc: add KNI behaviour change in release notes

Commit 89397a01ce4a ("kni: set default carrier state of interface")
changes the KNI interface default carrier status. Which prevents traffic
flow by default and may break some existing usage / testing.

Document this behavior change in release notes.

Fixes: c6fd54f28c24 ("kni: add function to set link state on kernel interface")
Fixes: 89397a01ce4a ("kni: set default carrier state of interface")
Fixes: 724beb913b44 ("examples/kni: monitor and update link state continually")

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index 95a187b..56011b4 100644 (file)
--- a/doc/guides/rel_notes/release_18_11.rst
+++ b/doc/guides/rel_notes/release_18_11.rst
@@ -404,6 +404,14 @@ API Changes
 * eventdev: Type of 2nd parameter to ``rte_event_eth_rx_adapter_caps_get()``
   has been changed from uint8_t to uint16_t.
 
+* kni: By default, interface carrier status is ``off`` which means there won't
+  be any traffic. It can be set to ``on`` via ``rte_kni_update_link()`` API
+  or via ``sysfs`` interface:
+  ``echo 1 > /sys/class/net/vEth0/carrier``.
+  Note interface should be ``up`` to be able to read/write sysfs interface.
+  When KNI sample application is used, ``-m`` parameter can be used to
+  automatically update the carrier status for the interface.
+
 
 ABI Changes
 -----------