On 30/04/2015 00:57, Denis Kenzior wrote:

Hi Alex,

It looks as though the issue is that the Cinterion parts don't support
signal strength via +CIND ?

Yes, we look for "signal" indicator inside cind_support_cb.  If it
isn't found, then we raise an error.  This tells the hw integrator to
address the issue.  CIND logic is provided as a fallback / default
since many manufacturers support this indicator for HFP.

signal_strength (and hence +CSQ) is used to bootstrap the signal
strength value.  This driver method is only called at very specific
times.  The core does not poll signal_strength.  It is expected that
the driver will send signal strength value to the core periodically,
by whatever means is optimal for the hardware.  Most modems use a
custom unsolicited notification or CIND to provide information about
signal strength automatically.  I suspect Cinterion has a similar
extension.

The consequence of the above is that it can't.  If no vendor extension
is available for unsolicited notifications and signal strength is not
provided via CIND, then the netreg atom driver can either poll signal
strength manually or simply not provide any signal strength updates.
For the latter, it must enable such behavior explicitly.  Hence why
your patch providing OFONO_VENDOR_CINTERION logic makes this work
properly.

Hope that made sense.

OK thanks for explaining that Denis. Yes, I was wondering if this was
related to the potential asynchronous nature of +CIND reporting versus
polling via at_signal_strength()

So, to make sure I understand...

The error message flags up a problem for the integrator. In the case of
OFONO_VENDOR_NOKIA, OFONO_VENDOR_SAMSUNG in at_creg_set_cb() we can
assume this has been investigated, and no good alternative event
reporting solution is available (or a choice was made not to implement)
so this is disabled.

However there remains an exercise to go through for Cinterion to check
whether non-CIND reporting mechanism is available and enable it? If so
I'll have a look through the documentation.

On a separate but related note, can you tell me if ofono supports
monitoring of signal strength whilst a data connection is up, e.g. via
use of GSM 07.10  or with modems such as Cinterion that expose multiple
virtual ports over USB?