Instantiating rmnet devices for data ports on QRTR-based modems

[Eric Caruso]

On Fri, Oct 16, 2020 at 12:40 PM Bjørn Mork <bjorn at mork.no> wrote:
>
> Aleksander Morgado <aleksander at aleksander.es> writes:
>
> > And an additional question I have; what if we start using QMAP also
> > for qmi_wwan based modems that support it? I think it would be very
> > similar to your current needs with QRTR/IPA, right? See
> > https://lists.freedesktop.org/archives/libqmi-devel/2018-July/002935.html
> > Maybe we can setup a common API in libqmi that brings up the muxed
> > network interfaces for both cases in a common way?
>
> Yes, that exact thought stroke me as well while skimming through this
> discussion. It would be nice if the API could abstract away the
> differences wrt adding network devices etc, and just present a common
> muxing API.

I haven't personally dealt with QMAP so I'm not really sure what's
going on there. The linked discussion does suggest a similar
architecture of one "real" net interface (wwan0 for QMAP, rmnet_ipa0
for QRTR/IPA) over which several "virtual" net ports are overlaid
(qmimuxN for QMAP, rmnet_dataN for QRTR/IPA).

Neither case would deal with QMI directly outside of the Bind Mux Data
Port message though, as far as I can tell. So I'm not sure if this is
an argument for keeping it in libqmi or not.

> Bjørn