Re: [RFC PATCH net-next 08/12] Documentation: networking: dsa: add paragraph for the LAG offload

[Vladimir Oltean <olteanv@gmail.com>]

On Thu, Feb 25, 2021 at 09:42:28PM +0100, Tobias Waldekranz wrote:
> On Sun, Feb 21, 2021 at 23:33, Vladimir Oltean <olteanv@gmail.com> wrote:
> > From: Vladimir Oltean <vladimir.oltean@nxp.com>
> >
> > Add a short summary of the methods that a driver writer must implement
> > for offloading a link aggregation group, and what is still missing.
> >
> > Cc: Tobias Waldekranz <tobias@waldekranz.com>
> > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> > ---
> >  Documentation/networking/dsa/dsa.rst | 32 ++++++++++++++++++++++++++++
> >  1 file changed, 32 insertions(+)
> >
> > diff --git a/Documentation/networking/dsa/dsa.rst b/Documentation/networking/dsa/dsa.rst
> > index 463b48714fe9..0a5b06cf4d45 100644
> > --- a/Documentation/networking/dsa/dsa.rst
> > +++ b/Documentation/networking/dsa/dsa.rst
> > @@ -698,6 +698,38 @@ Bridge VLAN filtering
> >    function that the driver has to call for each MAC address known to be behind
> >    the given port. A switchdev object is used to carry the VID and MDB info.
> >  
> > +Link aggregation
> > +----------------
> > +
> > +Link aggregation is implemented in the Linux networking stack by the bonding
> > +and team drivers, which are modeled as virtual, stackable network interfaces.
> > +DSA is capable of offloading a link aggregation group (LAG) to hardware that
> > +supports the feature, and supports bridging between physical ports and LAGs,
> > +as well as between LAGs. A bonding/team interface which holds multiple physical
> > +ports constitutes a logical port, although DSA has no explicit concept of a
> > +physical port at the moment. Due to this, events where a LAG joins/leaves a
> 
> s/physical/logical/ right?

Yes, brain fart #1.

> > +bridge are treated as if all individual physical ports that are members of that
> > +LAG join/leave the bridge. Switchdev port attributes (VLAN filtering, STP
> > +state, etc) on a LAG are treated similarly: DSA offloads the same switchdev
> > +port attribute on all members of the LAG. Switchdev objects on a LAG (FDB, MDB)
> > +are not yet supported, since the DSA driver API does not have the concept of a
> > +logical port ID.
> 
> Switchdev objects (MDB entries and VLANs) are supported, and will be
> added to all members of the LAG just like attributes. Static FDB entries
> are not switchdev objects though, and are therefore not supported.

And brain fart #2.