Re: [RFC PATCH net] net: dsa: tear down devlink port regions when tearing down the devlink port on error

On 9/7/2021 8:44 AM, Jakub Kicinski wrote:

On Sun, 5 Sep 2021 14:07:35 +0300 Vladimir Oltean wrote:

quoted

Again, fallback but not during devlink port register. The devlink port
was registered just fine, but our plans changed midway. If you want to
create a net device with an associated devlink port, first you need to
create the devlink port and then the net device, then you need to link
the two using devlink_port_type_eth_set, at least according to my
understanding.

So the failure is during the creation of the **net device**, we now have a
devlink port which was originally intended to be of the Ethernet type
and have a physical flavour, but it will not be backed by any net device,
because the creation of that just failed. So the question is simply what
to do with that devlink port.

Is the failure you're referring to discovered inside the
register_netdevice() call?

It is before, at the time we attempt to connect to the PHY device, prior 
to registering the netdev, we may fail that PHY connection, tearing down 
the entire switch because of that is highly undesirable.

Maybe we should re-order things a little bit and try to register devlink 
ports only after we successfully registered with the PHY/SFP and prior 
to registering the netdev?
-- 
Florian