On Thu, Aug 26, 2021 at 01:29:56PM +0800, DENG Qingfang wrote:

On Thu, Aug 26, 2021 at 03:03:49AM +0300, Vladimir Oltean wrote:

quoted

You cannot just remove the old code. Only things like 8021q uppers will
send packets with the VLAN in the hwaccel area.

If you have an application that puts the VLAN in the actual AF_PACKET
payload, like:

https://github.com/vladimiroltean/tsn-scripts/blob/master/isochron/send.c

then you need to handle the VLAN being in the skb payload.

I've actually tested this (only apply patch 2 without .features) and it
still worked.

The comment says the VLAN tag need to be combined with the special tag in
order to perform VLAN table lookup,

It does say this.

so we can set its destination port vector to all zeroes and the switch
will forward it like a data frame (TX forward offload),

And it does not say this. So this is supported after all with mt7530?
Are you looking to add support for that?

but as we allow multiple bridges which are either VLAN-unaware or
VLAN-aware with the same VID, there is no way to determine the
destination bridge unless we maintain some VLAN translation mapping.

What does "VLAN translation mapping" mean, practically?
Other drivers which cannot remap VIDs to internal VLANs just restrict a
single VLAN-aware bridge, and potentially multiple VLAN-unaware ones.