[PATCH] doc: update sample action description for mlx5

[Jiawei Wang]

This patch adds mlx5 description about E-Switch mirroring
flow (RTE_FLOW_ACTION_TYPE_SAMPLE with sample ratio=1) with
encap action, then supports the uplink port only in the sample
actions list or in the one flow.

Signed-off-by: Jiawei Wang <jiaweiw at nvidia.com>
---
 doc/guides/nics/mlx5.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index bb436892a0..81986253bf 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -432,6 +432,8 @@ Limitations
     sample actions list.
   - For E-Switch mirroring flow, supports ``RAW ENCAP``, ``Port ID``,
     ``VXLAN ENCAP``, ``NVGRE ENCAP`` in the sample actions list.
+  - For E-Switch mirroring flow, supports ``ENCAP`` actions only to the
+    UpLink Port and in either of sample actions list or in the flow.
   - For ConnectX-5 trusted device, the application metadata with SET_TAG index 0
     is not supported before ``RTE_FLOW_ACTION_TYPE_SAMPLE`` action.
 
-- 
2.18.1