[MM 0.6] Allowing plugins to specify that only one AT port is expected

[Aleksander Morgado <aleksander lanedo com>]

Hey,

The '06-api' branch has a new property
(MM_PLUGIN_BASE_ALLOWED_SINGLE_AT) for MMPluginBase, which allows
specifying that only one AT port is expected in the modem [1]. If this
property is set, whenever the first AT port is grabbed, all the
remaining port probings will cancel their AT-specific probing steps,
which improves a lot the overall time needed to finish device probing.
Of course, this property is only meaningful if the device exports
multiple ports where only one of them is AT. For single-port devices
(e.g. Cinterion) there is no improvement.

During my tests, I enabled the property for my Gobi 2000 and my Nokia C7
devices (which expose several ports, but end up grabbing only one AT
port here), and it works pretty well.

Now, the question is; should I enable this for every Gobi and Nokia
device? Are there Gobi-based or Nokia devices with more than one AT port
out there?

Also, is there any other plugin which could benefit from this probing
improvement?

Cheers,

[1] Plugins can now set either `MM_PLUGIN_BASE_ALLOWED_SINGLE_AT' or
`MM_PLUGIN_BASE_ALLOWED_AT'; no need to set both.

-- 
Aleksander