Re: [PATCH net] net: dsa: b53: skip EAP mode setup on Northstar SoCs when using port 5 or 7

Tested on an Asus RT-N18U (BCM53011 rev 5, CPU port 5). A build with
4227ea91e265 active and no workaround reproduces the regression: a
standalone port stops receiving entirely while its egress keeps working.
Untagged traffic on the wan port counted 9 frames out, all 9 arrived at
the peer, and 0 came back in. With this patch on the same build the port
receives again, untagged and tagged both, and the "skipping EAP setup
because of not using CPU port 8" line appears exactly once in dmesg.

Note on the setup: both builds also included my pending b53 standalone
VLAN series, the same on both sides, so the only difference between them
is this patch. The tagged test passes only because that series is
present; on plain mainline the tagged direction still fails for the
unrelated reason that series addresses. The untagged result does not
involve the series and shows this patch's effect on its own.

Tested-by: Semih Baskan <[email protected]>