[PATCH v3 2/2] doc: update PMD options for mlx5

[Yongseok Koh <yskoh@mellanox.com>]

Enhanced multi-packet send mode is newly introduced for ConnectX-5 families
of adaptors.

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---
 doc/guides/nics/mlx5.rst | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 41f3a472e..0783aebdd 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -183,10 +183,17 @@ Run-time configuration
 
 - ``txq_mpw_en`` parameter [int]
 
-  A nonzero value enables multi-packet send. This feature allows the TX
-  burst function to pack up to five packets in two descriptors in order to
-  save PCI bandwidth and improve performance at the cost of a slightly
-  higher CPU usage.
+  A nonzero value enables multi-packet send (MPS) for ConnectX-4 Lx and
+  enhanced multi-packet send (Enhanced MPS) for ConnectX-5. MPS allows the
+  TX burst function to pack up multiple packets in a single descriptor
+  session in order to save PCI bandwidth and improve performance at the
+  cost of a slightly higher CPU usage. When ``txq_inline`` is set along
+  with ``txq_mpw_en``, TX burst function tries to copy entire packet data
+  on to TX descriptor instead of including pointer of packet only if there
+  is enough room remained in the descriptor. ``txq_inline`` sets
+  per-descriptor space for either pointers or inlined packets. In addition,
+  Enhanced MPS supports hybrid mode - mixing inlined packets and pointers
+  in the same descriptor.
 
   This option cannot be used in conjunction with ``tso`` below. When ``tso``
   is set, ``txq_mpw_en`` is disabled.
@@ -194,6 +201,22 @@ Run-time configuration
   It is currently only supported on the ConnectX-4 Lx and ConnectX-5
   families of adapters. Enabled by default.
 
+- ``txq_mpw_hdr_dseg_en`` parameter [int]
+
+  A nonzero value enables including two pointers in the first block of TX
+  descriptor. This can be used to lessen CPU load for memory copy.
+
+  Effective only when Enhanced MPS is supported. Disabled by default.
+
+- ``txq_max_inline_len`` parameter [int]
+
+  Maximum size of packet to be inlined. This limits the size of packet to
+  be inlined. If the size of a packet is larger than configured value, the
+  packet isn't inlined even though there's enough space remained in the
+  descriptor. Instead, the packet is included with pointer.
+
+  Effective only when Enhanced MPS is supported. The default value is 256.
+
 - ``tso`` parameter [int]
 
   A nonzero value enables hardware TSO.
-- 
2.11.0