Re: [PATCH net] net: dsa: b53: prevent standalone from trying to forward to other ports

[Rafał Miłecki]

czw., 26 lut 2026 o 22:26 Florian Fainelli
<florian.fainelli@xxxxxxxxxxxx> napisał(a):
> On 2/26/26 12:24, Rafał Miłecki wrote:
> > W dniu 8.05.2025 o 11:14, Jonas Gorski pisze:
> >> When bridged ports and standalone ports share a VLAN, e.g. via VLAN
> >> uppers, or untagged traffic with a vlan unaware bridge, the ASIC will
> >> still try to forward traffic to known FDB entries on standalone ports.
> >> But since the port VLAN masks prevent forwarding to bridged ports, this
> >> traffic will be dropped.
> >>
> >> This e.g. can be observed in the bridge_vlan_unaware ping tests, where
> >> this breaks pinging with learning on.
> >>
> >> Work around this by enabling the simplified EAP mode on switches
> >> supporting it for standalone ports, which causes the ASIC to redirect
> >> traffic of unknown source MAC addresses to the CPU port.
> >>
> >> Since standalone ports do not learn, there are no known source MAC
> >> addresses, so effectively this redirects all incoming traffic to the CPU
> >> port.
> >
> > This change broke standalone ports (those not being part of bridge) on
> > Northstar (BCM5301X) devices. We got reports from users about WAN ports
> > on routers not working anymore:
> > https://github.com/openwrt/openwrt/issues/21187
> > https://github.com/openwrt/openwrt/issues/21349
> >
> > Can you take another look at those changes, see if something me be
> > wrong / missing?
>
> Checking the BCM5301X datasheet, the register definitions look correct.
>
> The first report appears to be for a Netgear R7000 which AFAICT would
> utilize port 8 of the switch as the CPU port, which would be correct.
>
> The other report is for a Netgear R6250 where port 5 would be acting as
> the CPU port, that could be an issue unless the switch is also
> programmed to use port 5 as the IMP port.
>
> Could you try to program GMNGCFG (page 0x02, offset 0) bits 7:6 to have
> the value 0b11 which is dual IMP port (IMPO is port 8 and IMP1 is port
> 5) and see if that helps?

On my Luxul XWR-3150 (it uses gmac0 and port 5) the value of
B53_MGMT_PAGE (0x02) / B53_GLOBAL_CONFIG (0x00) is 0xc2. Nothing to
set there I suppose?

-- 
Rafał