docs: Add flow control on i40e issue

There is an issue with flow control configuration on i40e devices and it has a work around. We add this to documentation as known issue until a permanent solution is developed. Signed-off-by: Tomasz Konieczny <[email protected]> Acked-by: Flavio Leitner <[email protected]> Signed-off-by: Ian Stokes <[email protected]>
trozet · Oct 6, 2020 · 39fbd2c · 39fbd2c
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diff --git a/Documentation/intro/install/dpdk.rst b/Documentation/intro/install/dpdk.rst
@@ -717,6 +717,15 @@ Limitations
   around is temporary and is expected to be removed once a method is provided
   by DPDK to query the upper bound MTU value for a given device.
 
+- Flow Control: When using i40e devices (Intel(R) 700 Series) it is recommended
+  to set Link State Change detection to interrupt mode. Otherwise it has been
+  observed that using the default polling mode, flow control changes may not be
+  applied, and flow control states will not be reflected correctly.
+  The issue is under investigation, this is a temporary work around.
+
+  For information about setting Link State Change detection, refer to
+  :ref:`lsc-detection`.
+
 Reporting Bugs
 --------------
 

diff --git a/Documentation/topics/dpdk/phy.rst b/Documentation/topics/dpdk/phy.rst
@@ -385,6 +385,8 @@ Jumbo Frames
 DPDK physical ports can be configured to use Jumbo Frames. For more
 information, refer to :doc:`jumbo-frames`.
 
+.. _lsc-detection:
+
 Link State Change (LSC) detection configuration
 -----------------------------------------------