Re: [PATCH net] net: bridge: switchdev: don't notify FDB entries with "master dynamic"

[Ido Schimmel]

On Wed, Apr 12, 2023 at 05:27:33PM +0300, Vladimir Oltean wrote:
> How are extern_learn FDB entries processed by spectrum's
> SWITCHDEV_FDB_ADD_TO_DEVICE handler?

No different than "BR_FDB_STATIC", which is a bug I'm aware of and
intend to fix in net-next when I get the time (together with all the
other combinations enabled by the bridge). Entry has ageing disabled,
but can roam in which case it becomes age-able.

TBH, I think most devices don't handle "BR_FDB_STATIC" correctly. In the
Linux bridge, "BR_FDB_STATIC" only means ageing disabled. The entry can
still roam, but remains "static". I believe that in most devices out
there "static" means no roaming and no ageing which is equivalent to
"BR_FDB_STATIC | BR_FDB_STICKY". Mentioned in your commit message as
well: "As for the hardware FDB entry, that's static, it doesn't move
when the station roams."

As it stands, the situation is far from perfect, but the patch doesn't
solve a regression (always broken) and will introduce one. My suggestion
allows you to move forward and solve the "dynamic" case, so let's
proceed with that unless there's a better alternative.