RE: [EXT] Re: [PATCH v6 3/3] net: dsa: ocelot: Add support for QinQ Operation

Hi Vladimir,

I asked this on the Microchip Support portal:

-----------------------------[cut here]-----------------------------

VLAN filtering only on specific TPID
------------------------------------

I would like to configure a port with the following behavior:
- The VLAN table should contain 802.1ad VLANs 1 and 10. VLAN ingress
filtering
  should be enabled.
- An untagged frame on ingress should be classified to 802.1ad (TAG_TYPE=1)
  VLAN ID 1 (the port-based VLAN). The frame should be accepted because
802.1ad
  VLAN 1 is in the VLAN table.
- An ingress frame with 802.1Q (0x8100) header VLAN ID 100 should be
classified
  to 802.1ad (TAG_TYPE=1) VLAN ID 1 (the port-based VLAN). The frame
should be
  accepted because 802.1ad VLAN 1 is in the VLAN table.
- An ingress frame with 802.1ad (0x88a8) header VLAN ID 10 should be
classified
  to 802.1ad (TAG_TYPE=1) VLAN ID 10. The frame should be accepted
because
  802.1ad VLAN 10 is in the VLAN table.
- An ingress frame with 802.1ad (0x88a8) header VLAN ID 100 should be
  classified to 802.1ad (TAG_TYPE=1) VLAN ID 100. The frame should be
dropped
  because 802.1ad VLAN 100 is not in the VLAN table.
How do I configure the switch to obtain this behavior? This is not what the
"Provider Bridges and Q-in-Q Operation" chapter in the reference manual is
explaining how to do. Instead, that chapter suggests to make
VLAN_CFG.VLAN_AWARE_ENA = 0. But I don't want to do this, because I need
to be able to drop the frames with 802.1ad VLAN ID 100 in the example above.

-----------------------------[cut here]-----------------------------

Judging from the fact that I received no answer whatsoever, I can only deduce
that offloading an 8021ad bridge, at least one that has the semantics that
Toshiaki Makita described here,
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kern
el.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fnetdev%2Fnet-next.git%2F
commit%2F%3Fid%3D1a0b20b257326523ec2a6cb51dd6f26ef179eb84&
data=02%7C01%7Chongbo.wang%40nxp.com%7Cdcfd5e5df4e24455726408d
86c4f0493%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6373784
33917654330&sdata=kk8WnA0iH9E5yPrLKC8BwSInD6jqm0qGftJ8Jw1Etk
8%3D&reserved=0
is not possible with this hardware.

So I think there's little left to do here.

If it helps, I am fairly certain that the sja1105 can offer the requested services,
if you play a little bit with the TPID and TPID2 values. Maybe that's a path
forward for your patches, if you still want to add the generic support in
switchdev and in DSA.

Thanks for your suggestion,
I will research the related code, and will optimize my patches.

Thanks,
hongbo