[dts][PATCH V5 5/8] test_plans/vlan_ethertype_config: modify script and test plan to support i40e fimware >= 8.4

[Weiyuan Li <weiyuanx.li@intel.com>]

Modify script and test plan to i40e support fimware >= 8.4.
When the fimrware >= 8.4, if the filter is to take effect need to enable
extend.

Signed-off-by: Weiyuan Li <weiyuanx.li@intel.com>
---
Tested-by: Song Jiale <songx.jiale@intel.com>

v2:
-use the firmware version to judge whether to add command `extend on`.
v3:
-modify description.
v4:
-modify comments.
-dual_vlan test plan modify table and add header.
v5:
-fix some typos.

 test_plans/vlan_ethertype_config_test_plan.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/test_plans/vlan_ethertype_config_test_plan.rst b/test_plans/vlan_ethertype_config_test_plan.rst
index 80a6ee28..7b145a9d 100644
--- a/test_plans/vlan_ethertype_config_test_plan.rst
+++ b/test_plans/vlan_ethertype_config_test_plan.rst
@@ -52,6 +52,10 @@ Test Case 2: test VLAN filtering on/off
       testpmd> vlan set filter on 0
       testpmd> start
 
+      Due to the kernel enables Qinq and cannot be closed, the DPDK only add `extend on` to make the VLAN filter
+      work normally. Therefore, if the i40e firmware version >= 8.4 the DPDK can only add `extend on` to make the VLAN filter work normally:
+      testpmd> vlan set extend on 0
+
 2. Send 1 packet with VLAN TPID 0xA100 and VLAN Tag 16 on port ``A``,
    Verify that the VLAN packet cannot be received in port ``B``.
 
@@ -77,6 +81,10 @@ Test Case 3: test adding VLAN Tag Identifier with changing VLAN TPID
       testpmd> vlan set strip off 0
       testpmd> start
 
+      Due to the kernel enables Qinq and cannot be closed, the DPDK only add `extend on` to make the VLAN filter
+      work normally. Therefore, if the i40e firmware version >= 8.4 the DPDK can only add `extend on` to make the VLAN filter work normally:
+      testpmd> vlan set extend on 0
+
 2. Add a VLAN Tag Identifier ``16`` on port ``0``::
 
       testpmd> rx_vlan add 16 0
-- 
2.27.0