net: config: Add VLAN identifier as network initial configuration

[luca-fancellu]

Add a new Kconfig parameter NET_CONFIG_MY_VLAN_ID as initial network configuration to enable users to set VLAN identifier at startup.

Add a call in net_config_init_by_iface(...) function to setup the VLAN identifier in the device if the Kconfig parameter is different from zero.

[jukkar]

I have small reservations for putting VLAN setup to config lib as this allows only one VLAN tag to be set (if that is enough then all is good). That is why I originally did not put any VLAN configuration code here but instead had a samples/net/vlan that shows how the application can setup the tags itself. So this PR certainly works but has limitations.

I think the config library is starting to show its limitations as it only supports to setup one instance of a "thing" only. In the past @cfriedt suggested using dt to configure networking config options and with dt we could have a configuration setup for multiple instances of things. Someone would just need to define dt options for networking.

So +1 from me but with reservations.

[carlescufi]

I think the config library is starting to show its limitations as it only supports to setup one instance of a "thing" only. In the past @cfriedt suggested using dt to configure networking config options and with dt we could have a configuration setup for multiple instances of things. Someone would just need to define dt options for networking.

Ultimately I think this is going to be the correct solution, because DT is the only way we have to configure multi-instance devices and hardware in general.

[luca-fancellu]

@jukkar @carlescufi Hi! Can you point me to the discussion about that? We are definitely interested in setting up more than one device at boot time and we can spend some time for that, I've thought before we could use DT but I was not sure until now, because you mention that.
So if you have already a design I think we can work on that feature, as long as it meets our requirements.
Also, is there a space where people can discuss these kind of things, like a chat or something? A forum?

Thanks :)

[pdgendt]

There is a big reservation with using DT for describing software "metadata" rather than hardware information. See
#49431
#50441
And probably more...

[pdgendt]

Also, is there a space where people can discuss these kind of things, like a chat or something? A forum?

You can join the discord chat (recommended), or use the mailing lists.

[carlescufi]

Also, is there a space where people can discuss these kind of things, like a chat or something? A forum?

@luca-fancellu
https://chat.zephyrproject.org/

Then join the #networking channel

[carlescufi]

There is a big reservation with using DT for describing software "metadata" rather than hardware information. See #49431 #50441 And probably more...

Thanks @pdgendt. I think we are going to have to bring this to the Architecture WG, because USB had the same problem and they ended up using DT for this.
Also see #29750

@pdgendt @rlubos @luca-fancellu @jukkar let's continue the discussion on Discord. @luca-fancellu feel free to start a thread there