On Wed, Sep 8, 2021 at 10:10 PM Vladimir Oltean [off-list ref] wrote:

Your interpretation seems correct (I can't think of anything else being meant),
but I don't know why you say "duh" about the update of STP state
resulting in the port losing its dynamic L2 entries. Sure, it makes
sense, but many other vendors do not do that automatically, and DSA
calls .port_fast_age whenever the STP state transitions from a value
capable of learning (LEARNING, FORWARDING) to one incapable of learning
(DISABLED, BLOCKING, LISTENING).

To prove/disprove, it would be interesting to implement port STP states,
without implementing .port_fast_age, force a port down and then back up,
and then run "bridge fdb" and see whether it is true that STP state
changes also lead to FDB flushing but at a hardware level (whether there
is any 'self' entry being reported).

I have been looking into this.

What makes RTL8366RB so confusing is a compulsive use of FIDs.

For example Linux DSA has:

ds->ops->port_stp_state_set(ds, port, state);

This is pretty straight forward. The vendor RTL8366RB API however has this:

int32 rtl8368s_setAsicSpanningTreeStatus(enum PORTID port, enum
FIDVALUE fid, enum SPTSTATE state)

So this is set per FID instead of per VID.

I also looked into proper FDB support and there is the same problem.
For example I want to implement:

static int rtl8366rb_port_fdb_add(struct dsa_switch *ds, int port,
                  const unsigned char *addr, u16 vid)

But the FDB static (also autolearn) entries has this format:

struct l2tb_macstatic_st{
    ether_addr_t     mac;
    uint16     fid:3;
    uint16     reserved1:13;
    uint16     mbr:8;
    uint16     reserved2:4;
    uint16    block:1;
    uint16     auth:1;
    uint16     swst:1;
    uint16     ipmulti:1;
    uint16     reserved3;
};

(swst indicates a static entry ipmulti a multicast entry, mbr is apparently
for S-VLAN, which I'm not familiar with.)

So again using a FID rather than port or VID in the database.

I am starting to wonder whether I should just associate 1-1 the FID:s
with the 6 ports (0..5) to simplify things. Or one FID per defined VID
until they run out, as atleast OpenWRT connects VLAN1 to all ports on
a bridge.

Yours,
Linus Walleij