[PATCH] Infineon: Add support for Infineon / Intel modems

[Aleksander Morgado]

On Sat, Jun 10, 2017 at 3:25 AM, Paul Bartell <paul.bartell at gmail.com> wrote:
> I don't have any modems to test ECM data mode with. Likely It could be
> supported via the +XDATACHANNEL command in addition to +XCEDATA, but
> It's unclear from the Sierra interface guide or Intel docs.
>
> Either way, we will have to add more VID/PID pairs for other modems /
> USB compositions to support modems with the ECM data feature.
>
> The Telit LN930 seems to share a USB VID/PID with the HL7588 in NCM
> mode, so it's probably a good idea to test with that modem as well so
> that we don't break compatibility (it supposedly works with the
> generic plugin as-is).
>
> I attached a new patch that should address your other requests. Let me
> know if there are any other issues or if I missed anything.

I've pushed this last patch to the "paul/infineon" branch in upstream
git. I'll likely go over it and suggest some changes on top as soon as
I have some free time.

In particular, I am still not convinced that we should deactivate a
context to "reconfigure" it. We don't do anything like this in any
other plugin, which is why it bugs me a bit. Questions that arise from
this issue:
  * Why is the context activated in the first place, is it auto-activated?
  * Why would you want to reconfigure the context? The cid given in
dial_3gpp() is the one which matched the APN+IP type settings already.
Is this to have proper XDNS responses later on?
  * The deactivation is skipped if cid=1; assuming this is the default
LTE bearer that you don't want to get disconnected as we would get
unregistered; but this cid, is it operator-dependent or hw-dependent?
(e.g. isn't the default bearer for Verizon defined in #3?), is it
configurable? can we ask the modem which is the cid of the default lte
bearer? We don't have any other logic depending on a fixed cid number
anywhere yet.

One of the things that is in my pending todo list is the support for
"autoconnected" bearers; e.g. so that MM exposes in DBus bearers
automatically if they are already connected. I'm assuming this could
actually be a usecase for this new feature, e.g. if we detect that a
given pdp context is connected already.

Another thing in my pending todo list is the ability to
list/add/remove/edit contexts/profiles. I'm still unsure how to best
do this given that the APN of the default LTE bearer exposed in e.g.
AT+CGDCONT? will/may be different depending on whether it's registered
in LTE or not, but well...

-- 
Aleksander
https://aleksander.es