Re: [PATCH 2/4] voicecall: add ATD support for HFP emulator

[Denis Kenzior <denkenz@gmail.com>]

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Hi Frederic,

>>> +    if (!strncmp(number, "*31#", 4)) {
>>> +        number += 4;
>>> +        clir = OFONO_CLIR_OPTION_INVOCATION;
>>> +    } else if (!strncmp(number, "#31#", 4)) {
>>> +        number += 4;
>>> +        clir =  OFONO_CLIR_OPTION_SUPPRESSION;
>>> +    } else
>>> +        clir = OFONO_CLIR_OPTION_DEFAULT;
>>> +
>>
>> Actually this is not quite right.  The clir option is determined by the
>> presence of 'I'/'i' characters at the end of the dial string.  Refer to
>> 27.007 for more details.
>>
>> oFono does not actually recognize temporary forms of *31/#31
>> invocation yet.
>>
> I added *31/#31 as I found them in telephony-ofono implementation of
> BlueZ HFP AG,
> but 27.007 uses I/i,
> and HFP 1.5 does not seem to support clir option (ATDdd...dd;)
> 
> Should I remove this part of code and only be compatible with HFP specs ?
> 

Might as well handle the I/i and G/g part according to 27.007 since that
is pretty easy and we'll have to do it anyway.  *31/#31 is really an MMI
code, it should never be sent to the modem, so please remove that for now.

>>> +    err = voicecall_dial(vc, number, clir, emulator_dial_callback, vc);
>>> +    switch (err) {
>>> +    case DIAL_NO_ERROR:
>>> +        result.type = OFONO_ERROR_TYPE_NO_ERROR;
>>> +        break;
>>> +
>>> +    case DIAL_NO_NETWORK:
>>> +        result.error = 30;
>>> +        result.type = OFONO_ERROR_TYPE_CME;
>>> +        break;
>>
>> This might need to be NO CARRIER
>>
> As far as I understand, when there is no network, ATD should reply NO
> CARRIER if CMEE error mode is set to 0, or +CME ERROR: 30 if it is set
> to 1.

Not quite.  CMEE controls the presentation of 'extended' CME ERROR code.
 Either as ERROR, CME ERROR: <num> or CME ERROR: <str>.  NO CARRIER is
not an extended error code at all, and so is only affected by ATV
setting, not CMEE.

> So, I think that voicecall should return an OFONO_ERROR_TYPE_CME 30, and
> ofono_emulator_send_final should take care of replying the right string.
> 

Nope, you have to take your pick, either CME ERROR: 30, or NO CARRIER.
I'd expect most implementations to reply with a NO CARRIER in this case,
but can you check what other implementations do in reality?

Regards,
-Denis