Re: [PATCH net-next 1/4] net: dsa: don't offload switchdev objects on ports that don't offload the bridge

[Tobias Waldekranz <tobias@waldekranz.com>]

On Sun, Feb 14, 2021 at 17:53, Vladimir Oltean <olteanv@gmail.com> wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> Starting with commit 058102a6e9eb ("net: dsa: Link aggregation support"),
> DSA warns that certain configurations of upper interfaces are not offloaded
> to hardware. When a DSA port does not offload a LAG interface, the
> dp->lag_dev pointer is always NULL. However the same cannot be said about
> offloading a bridge: dp->bridge_dev will get populated regardless of
> whether the driver can put the port into the bridge's forwarding domain
> or not.
>
> Instead of silently returning 0 if the driver doesn't implement
> .port_bridge_join, return -EOPNOTSUPP instead, and print a message via
> netlink extack that the configuration was not offloaded to hardware.
>
> Now we can use the check whether dp->bridge_dev is NULL in order to
> avoid offloading at all switchdev attributes and objects for ports that
> don't even offload the basic operation of switching. Those can still do
> the required L2 forwarding using the bridge software datapath, but
> enabling any hardware features specific to the bridge such as address
> learning would just ask for problems.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---

Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>