Re: [RFC PATCH 08/10] net: dsa: b53: fix unicast/multicast flooding on BCM5325

[Jonas Gorski]

On Mon, Jun 2, 2025 at 8:09 PM Florian Fainelli
<florian.fainelli@xxxxxxxxxxxx> wrote:
>
> On 5/31/25 03:13, Álvaro Fernández Rojas wrote:
> > BCM5325 doesn't implement UC_FLOOD_MASK, MC_FLOOD_MASK and IPMC_FLOOD_MASK
> > registers.
> > This has to be handled differently with other pages and registers.
> >
> > Fixes: a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags")
> > Signed-off-by: Álvaro Fernández Rojas <noltari@xxxxxxxxx>
> > ---
>
> [snip]
>
> > +/*************************************************************************
> > + * IEEE 802.1X Registers
> > + *************************************************************************/
> > +
> > +/* Multicast DLF Drop Control register (16 bit) */
> > +#define B53_IEEE_MCAST_DLF           0x94
> > +#define B53_IEEE_MCAST_DROP_EN               BIT(11)
> > +
> > +/* Unicast DLF Drop Control register (16 bit) */
> > +#define B53_IEEE_UCAST_DLF           0x96
> > +#define B53_IEEE_UCAST_DROP_EN               BIT(11)
>
> Are you positive the 5325 implements all of those registers? They are
> not documented in my databook.

They are in 5325E-DS14-R pages 112 - 112 (134/135)

That being said, I don't thing we need to touch the MC/BC/DLF rate
control registers when enabling/disabling flooding - these only limit
how much traffic may be UC / MC  on a port, but apart from that they
do not limit flooding. We don't limit this on other switch models
either.

Regards,
Jonas