Hi Florian, Florian Fainelli <f.faine...@gmail.com> wrote on Fri, 25 Jan 2019 10:37:38 -0800:
> Hi Miquel, > > On 1/25/19 1:55 AM, Miquel Raynal wrote: > > The user might apply a specific switch configuration, with specific > > forwarding rules, VLAN, bridges, etc. > > > > During suspend to RAM the switch power will be turned off and the > > switch will lost its configuration. In an attempt to bring S2RAM > > support to the mv88e6xxx DSA, let's first save these rules in a > > per-chip list thanks to the mv88e6xxx_add/del_xxx_rule() > > helpers. These helpers are then called from various callbacks: > > * mv88e6xxx_port_fdb_add/del() > > * mv88e6xxx_port_mdb_add/del() > > * mv88e6xxx_port_vlan_add/del() > > * mv88e6xxx_port_bridge_join/leave() > > * mv88e6xxx_crosschip_bridge_join/leave() > > > > To avoid recursion problems when replaying the rules, the content of > > the above *_add()/*_join() callbacks has been moved in separate > > helpers with a '_' prefix. Hence, each callback just calls the > > corresponding helper and the corresponding *_add_xxx_rule(). > > None of this should be done in the driver IMHO, because this is > presumably applicable to all switch devices that lose their state during > suspend/resume, so at best, this should be moved to the core DSA layer, > but doing this means that we should also have a well established > contract between the DSA layer and individual switch drivers as far as > quiescing/saving/restoring state goes. > > By moving things to the core we can also more tightly control what data > structures get used to represent e.g.: VLANs, FDBs, MDBs etc and > possibly push/utilize caching into the original subsystem. For instance > VLAN/bridge already do maintain caches of VLANs, so if we could somehow > expose those, we would not bloat the kernel's memory footprint by having > an additional layer to maintain with identical information. So you suggest to move the intelligence of FDBs/MDBs in net/dsa/port.c, is this right? I don't see where VLAN and bridge information are cached, can you point me to the relevant locations? What about cross-chip bridges? There is nothing about them in net/dsa/port.c. The implementation I see in the mv88e6xxx driver only touches the PVT but I don't get whether we should handle this calls like regular bridge-join/leave events or not (maybe they are cached with regular bridge events?). Thanks, Miquèl
