Hi Johannes,

After all, I'm not really proposing that we put oFono or something like
it into the kernel - far from it! I'm only proposing that we kill the
many various ways of creating and managing the necessary netdevs (VLANs,
sysfs, rmnet, ...) from a piece of software like oFono (or libmbim or
whatever else).

I do like the concept of unifying this if possible.  The question is, is 
it actually possible :)  I think Dan covered most of the aspects of what 
userspace has to deal with already.  But the basic issue is that there's 
a heck of a lot of different ways of doing it.

Apart from CAIF and phonet, oFono doesn't even try to do this though,
afaict, so I guess it relies on the default netdev created, or some out-
of-band configuration is still needed?

Actually it can.  We can drive modems which provide only a single serial 
port and run multiplexing over that.  So we fully control the number of 
control channels created, the number of netdevs created and even 
create/destroy them on as needed basis.  And these netdevs can be PPP 
encapsulated or pure IP or whatever else.

Regards,
-Denis