Subject: Re: [PATCH v2 net-next 2/6] net: dsa: propagate flags down towards drivers

From: Hans Schultz <[email-masked]>
Date: Tue, 28 Mar 2023 21:45:26 +0200

On Tue, Mar 28, 2023 at 14:49, Vladimir Oltean <[email-masked]> wrote:
> On Tue, Mar 28, 2023 at 01:04:23PM +0200, Hans Schultz wrote:
>> On Tue, Mar 28, 2023 at 01:59, Vladimir Oltean <[email-masked]> wrote:
>> >
>> > which idea is that, again?
>> 
>> So I cannot us the offloaded flag as it is added by DSA in the common
>> case when using 'bridge fdb replace ... dynamic'.
>
> Why not? I find it reasonable that the software bridge does not age out
> a dynamic FDB entry that is offloaded to hardware... the hardware should
> do that ("dynamic" being the key).

So the solution would be to not let the DSA layer send the
SWITCHDEV_FDB_OFFLOADED event in the case when the new dynamic flag is
set?
Thus other drivers that don't support the flag yet will install a
static entry in HW and the bridge will age it out as there is no offloaded
flag on. For the mv88e6xxx it will set the offloaded flag and HW will
age it.

> At least, I find it more reasonable
> than the current behavior, where the bridge notifies dynamic FDB entries
> to switchdev, but doesn't say they're dynamic, and switchdev treats them
> as static, so they don't roam from one bridge port to another until
> software sees a packet with that MAC DA, and they have the potential of
> blocking traffic because of that.
>