We have assumed until now that all QCDM ports are based on TTY
drivers, e.g. exposed via USB.
This may no longer be true, so allow creating QCDM ports with
an explicit subsystem instead of defaulting always to TTY.
mm-port-serial-qcdm.c: In function ‘find_qcdm_start’:
mm-port-serial-qcdm.c:51:19: error: comparison of integer expressions of different signedness: ‘int’ and ‘guint’ {aka ‘unsigned int’} [-Werror=sign-compare]
51 | for (i = 0; i < response->len; i++) {
| ^
By default all the commands we were sending through the serial port
were added at the tail of the pending queue, but we may want to queue
them at the head in very specific cases (e.g. while sending an SMS).
When a CDMA-only modem is registered with the EVDO network, its not possible to
read signal strength in the following cases:
1) while a data connection is active on single-AT-port modems, because the AT
port is used for PPP and not available for AT+CSQ, AT+CIND or vendor-specific
signal strength commands
2) when the modem reports only CDMA 1x signal strength with AT+CSQ
Now that we have a reasonable interpretation of RSSI from the QCDM
EVDO Pilot Sets V2 log messgae, use that when other means of getting
signal strength aren't available.
Response parsing was being done in different places for AT and QCDM subclasses;
in the case of AT it was being done early, before returning the byte array in
the mm_serial_port_command_finish() response. In the case of QCDM, it was being
done after mm_serial_port_command_finish(), and that was forcing every caller to
cleanup the response buffer once the response was processed.
With the new logic in this patch, the response is always parsed (i.e. looked for
a valid response or an error detected) before mm_serial_port_command_finish()
returns, and actually this method now returns a totally different GByteArray,
not the internal response buffer GByteArray, so there's no longer any need for
the caller to explicitly clean it up. The one doing the cleanup is the parser
method itself in every case.
This change also allows us to return serial port responses in idle, but that's
not changed for now as there's no immediate need.
The QCDM port commands are never cached, so remove the option from the command()
method. Will also simplify command caching afterwards as it will be an AT-only
thing.
Aleksander Morgado
Ben Chan
Dan Williams