Re: [PATCH 5/8] lte: activate default bearer on network registration

[Denis Kenzior <denkenz@gmail.com>]

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Hi Jonas,

On 04/11/2017 03:48 PM, Jonas Bonn wrote:
> Hi Denis,
>
> On 04/11/2017 07:07 PM, Denis Kenzior wrote:
>> On 04/11/2017 03:18 AM, Jonas Bonn wrote:
>>> The LTE atom should watch the network status and automatically activate
>>> the default bearer when the modem becomes registered to the LTE network.
>>>
>>> This patch adds a device callback, activate_default_bearer(), to allow
>>> the device to start networking.
>>
>> Nope, we're not doing it this way.  Once we're attached to LTE there's
>> no need to activate a default bearer.  It is already active.  The
>> modem should tell us that this is the case.
>>
>> Another issue is that the network is free to ignore our default bearer
>> setting, so you might be activating (or trying to) yet another context.
>>
>> Doesn't QMI provide an equivalent of +CGEV?
>
> I haven't found an equivalent.  Right now it looks to me as though the
> only way to set up a PDP context is to call the "Start Networking"
> method.  If I don't start networking, the packet status callback never
> gives me a "connected" status.  It's not enough to just power on the
> modem... although that does get me registered to the network.

QMI is an ancient protocol, so maybe it simply didn't get extended for 
LTE.  Or we just don't know how to drive it properly.  Is there an AT 
channel ?  Does that one report anything related to CGEV?

>
> Furthermore, it doesn't matter what APN I use, I always get a usable
> data-connection.  "Get Settings" never returns an APN string, either,
> which makes me that the network is ignoring my setting altogether and
> just giving me a default bearer...???

The network is ultimately responsible for allocating an APN.  It could 
be blank or null or whatever.  Or maybe we don't know the right magic 
incantation.

Regards,
-Denis