ede17bd41c
When valid responses were returned to the caller of the serial command, the
caller itself was responsible for removing from the GByteArray the data that
it was successfully processed (all the data in AT, just 1 message in QCDM). But,
the same logic was missing for the case of errors; we were not explicitly
removing the response and therefore in some cases we would see it propagated
into the next command response. It was common to see this issue when the echo
removal was disabled in the serial port, as in Option/HSO modems:
<debug> (ttyHS3): --> 'AT+CNUM<CR>'
<debug> (ttyHS3): <-- '<CR><LF>+CME ERROR: 14<CR><LF>'
<debug> Got failure code 14: SIM busy
<debug> (ttyHS3) device open count is 1 (close)
<warn> couldn't load list of Own Numbers: 'Failed to parse NV MDN command result: -17'
<debug> (ttyHS3) device open count is 2 (open)
<debug> (ttyHS3): --> 'AT_OPSYS?<CR>'
<debug> (ttyHS3): <-- '<CR><LF>_OPSYS: 1,2<CR><LF><CR><LF>OK<CR><LF>'
<warn> couldn't load current allowed/preferred modes: 'Couldn't parse OPSYS response: '+CME ERROR: 14
_OPSYS: 1,2''
ModemManager. ModemManager provides a unified high level API for communicating with mobile broadband modems, regardless of the protocol used to communicate with the actual device (Generic AT, vendor-specific AT, QCDM, QMI, MBIM...). Using. ModemManager is a system daemon and is not meant to be used directly from the command line. However, since it provides a DBus API, it is possible to use 'dbus-send' commands or the new 'mmcli' command line interface to control it from the terminal. The devices are queried from udev and automatically updated based on hardware events, although a manual re-scan can also be requested to look for RS232 modems. Implementation. ModemManager is a DBus system bus activated service (meaning it's started automatically when a request arrives). It is written in C, using glib and gio. Several GInterfaces specify different features that the modems support, including the generic MMIfaceModem3gpp and MMIfaceModemCdma which provice basic operations for 3GPP (GSM, UMTS, LTE) or CDMA (CDMA1x, EV-DO) modems. If a given feature is not available in the modem, the specific interface will not be exported in DBus. Plugins. Plugins are loaded on startup, and must implement the MMPlugin interface. It consists of a couple of methods which tell the daemon whether the plugin supports a port and to create custom MMBroadbandModem implementations. It most likely makes sense to derive custom modem implementations from one of the generic classes and just add (or override) operations which are not standard. There are multiple fully working plugins in the plugins/ directory that can be used as an example for writing new plugins. Writing new plugins is highly encouraged! The plugin API is open for changes, so if you're writing a plugin and need to add or change some public method, feel free to suggest it! License. The ModemManager and mmcli binaries are both GPLv2+. The libmm-glib library is LGPLv2+.