Hi Denis,

Den ons 19 feb. 2020 kl 19:52 skrev Denis Kenzior <denkenz@gmail.com>:
Hi Richard,

On 2/18/20 3:19 AM, Richard Röjfors wrote:
> Hi,
>
> Ofono (at least for ublox) is always powering off the radio during start.
> This can of course be handy of programmatic reasons to bring the modem
> to a known state.
> Some configuration requires the radio to be turned off;  for instance
> the LTE auto connect APN. But on the other hand these are stored in
> non-volatile memory and could be configured before hand.

So by default we bring the device into airplane mode until the SIM card
has been initialized.  Also, the policy decision of bringing the radio
up / down was left to external services such as ConnMan.

>
> The big drawback with turning it off is that it might take time to
> register again when the radio is on. I have seen it taking more than 10
> minutes in extreme cases.
>

That's nuts.  Shouldn't take more than a few seconds?

I would assume so too, but that's what we have experienced.
 

> In embedded systems this can be a big issue.
>

Indeed.

> I'm thinking of adding a configuration option to keep the radio on
> during start.
>
> Whats the general thought about this?
>

Not sure.  Are you certain that adding such low-level config options is
the right approach?

I'm not sure thats why I started the discussion. The other suggestion
in this thread was to use some environment variable to pass the
information, maybe thats a better way?
 
  Even documenting / explaining what and why this
configuration option is there would be challenging I imagine.

Yes it will be. I think I'm convinced we should not have this
feature upstreams.

--Richard