On a ZTE MF626, sometimes the aux port will respond only with
"ERROR" to probing commands (while the SIM is starting up) and
previously we'd lose the port because we were only looking for
valid probe responses. But if the port returns ERROR or CME ERROR
etc we know it's an AT port and that we can use it once we've
gotten the type response (CDMA or GSM) from the main port.
We need to ensure that the supports task always has the results of the probing,
no matter if the probing was just launched by the plugin grabbing the port, or
by a previous plugin. We do this during supports_port(), by propagating to the
supports task any possible previously cached probing results.
Note that even if a plugin says it wants to be sorted last, the generic plugin
will always be the last one. Also, there is no order guaranteed between two
plugins that request to be sorted last.
Port probing is extended to also query for Vendor ID and Product ID. This allows
plugins to check whether the reported IDs are expected, and thus we enable
plugins to handle modems connected via RS232 ports (where udev doesn't give any
vendor ID) or modems connected via a USB adapter (where udev gives the vendor ID
of the adapter).
Note that this effectively means that a plugin which expects these kind of modem
connections will end up always launching port probing as they won't only rely on
the vendor ID reported by udev.
Previously plugins could only stop probing, *or* stop probing and
indicate support for a device. For the Alcatel X200/X060s debacle
we need to stop probing and indicate that the plugin does not
support the device at all.
Instead of having two places that custom init stuff got processed
(a hook in the MMPluginBase class itself and a callback too) just
use a callback, and simplify it somewhat so that the plugin tracks
how many tries it cares about and what to do based on the response
or error.
This implements the same fixes that NetworkManager's 0.7 branch
implemented in commits f38ad328acfdc6ce29dd1380602c546b064161ae and
1235f71b20c92cded4abd976ccc5010649aae1a0. Many ZTE devices will
spam the port with messages about waiting voicemail/SMS which buffer
up and cause the device to eventually crash if not suppressed.
Allow plugins to perform asynchronous port detection, and to defer port detection
until later. This moves the prober bits into MMPluginBase so that all plugins
can take adavantage of it only when needed; the probing is not done at udev time.
Furthermore, plugins like Novatel can flip the secondary ports over the AT mode
through deferred detection, by deferring the secondary ports until the main port
has been detected and AT$NWDMAT has been sent.
This commit also finishes the port of the rest of the plugins (except mbm) over
to the new port detection methods and plugin API.
