Re: [PATCH v1 1/2] driver core: fw_devlink: Add support for FWNODE_FLAG_BROKEN_PARENT

[Vladimir Oltean]

Hi Saravana,

On Wed, Sep 29, 2021 at 10:33:16PM -0700, Saravana Kannan wrote:
> On Tue, Aug 31, 2021 at 4:18 PM Vladimir Oltean <olteanv@xxxxxxxxx> wrote:
> >
> > On Wed, Sep 01, 2021 at 01:02:09AM +0200, Andrew Lunn wrote:
> > > Rev B is interesting because switch0 and switch1 got genphy, while
> > > switch2 got the correct Marvell PHY driver. switch2 PHYs don't have
> > > interrupt properties, so don't loop back to their parent device.
> >
> > This is interesting and not what I really expected to happen. It goes to
> > show that we really need more time to understand all the subtleties of
> > device dependencies before jumping on patching stuff.
> >
> > In case the DSA tree contains more than one switch, different things
> > will happen in dsa_register_switch().
> > The tree itself is only initialized when the last switch calls
> > dsa_register_switch(). All the other switches just mark themselves as
> > present and exit probing early. See this piece of code in dsa_tree_setup:
> >
> >         complete = dsa_tree_setup_routing_table(dst);
> >         if (!complete)
> >                 return 0;
> 
> Hi Vladimir,
> 
> Can you point me to an example dts file that has a DSA tree with more
> than one switch and also point me to the switches that form the tree?
> 
> I'm working on a RFC series that tries to improve some stuff and
> having an example DTS to look at would help.
> 
> Thanks,
> Saravana

Andrew is testing with arch/arm/boot/dts/vf610-zii-dev-rev-b.dts.

Graphically it looks like this:

 +-----------------------------+
 |          VF610 SoC          |
 |          +--------+         |
 |          |  fec1  |         |
 +----------+--------+---------+
                | DSA master
                |
                | ethernet = <&fec1>;
 +--------+----------+---------------------------+
 |        |  port@6  |                           |
 |        +----------+                           |
 |        | CPU port |     dsa,member = <0 0>;   |
 |        +----------+      -> tree 0, switch 0  |
 |        |   cpu    |                           |
 |        +----------+                           |
 |                                               |
 |            switch0                            |
 |                                               |
 +-----------+-----------+-----------+-----------+
 |   port@0  |   port@1  |   port@2  |   port@5  |
 +-----------+-----------+-----------+-----------+
 |switch0phy0|switch0phy1|switch0phy2|   no PHY  |
 +-----------+-----------+-----------+-----------+
 | user port | user port | user port | DSA port  |
 +-----------+-----------+-----------+-----------+
 |    lan0   |    lan1   |    lan2   |    dsa    |
 +-----------+-----------+-----------+-----------+
                                           | link = <&switch1port6 &switch2port9>;
                                           |
                                           |
                                           |
                                           | link = <&switch0port5>;
                           +----------+----------+-------------------------+
                           |          |  port@6  |                         |
                           |          +----------+                         |
                           |          | DSA port |    dsa,member = <0 1>;  |
                           |          +----------+     -> tree 0, switch 1 |
                           |          |   dsa    |                         |
                           |          +----------+                         |
                           |                                               |
                           |            switch1                            |
                           |                                               |
                           +-----------+-----------+-----------+-----------+
                           |   port@0  |   port@1  |   port@2  |   port@5  |
                           +-----------+-----------+-----------+-----------+
                           |switch1phy0|switch1phy1|switch2phy2|   no PHY  |
                           +-----------+-----------+-----------+-----------+
                           | user port | user port | user port | DSA port  |
                           +-----------+-----------+-----------+-----------+
                           |    lan3   |    lan4   |    lan5   |   dsa     |
                           +-----------+-----------+-----------+-----------+
                                                                    | link = <&switch2port9>;
                                                                    |
                                                                    |
                                                                    |
                                                                    | link = <&switch1port5 &switch0port5>;
                                                    +----------+----------+-------------------------------------+
                                                    |          |  port@9  |                                     |
                                                    |          +----------+                                     |
                                                    |          | DSA port |      dsa,member = <0 2>;            |
                                                    |          +----------+       -> tree 0, switch 2           |
                                                    |          |   dsa    |                                     |
                                                    |          +----------+                                     |
                                                    |                                                           |
                                                    |            switch2                                        |
                                                    |                                                           |
                                                    +-----------+-----------+-----------+-----------+-----------+
                                                    |   port@0  |   port@1  |   port@2  |   port@3  |   port@4  |
                                                    +-----------+-----------+-----------+-----------+-----------+
                                                    |switch2phy0|switch2phy1|switch2phy2|   no PHY  |   no PHY  |
                                                    +-----------+-----------+-----------+-----------+-----------+
                                                    | user port | user port | user port | user port | user port |
                                                    +-----------+-----------+-----------+-----------+-----------+
                                                    |    lan6   |    lan7   |   lan8    |  optical3 |  optical4 |
                                                    +-----------+-----------+-----------+-----------+-----------+