Re: [MM] Question regarding minimum probing time in MMPluginManager

[Dan Williams <dcbw redhat com>]

On Fri, 2013-06-28 at 09:32 +0200, Aleksander Morgado wrote:
> > As always, we're very motivated to shave a second or a few hundred
> > milliseconds off the modem startup time :)
> >
> > I guess a simple solution is to let a plugin specify the max number of
> > ports N, such that the plugin manager will skip the minimum probing
> > time after seeing the completion of N port probes.   A more generic
> > solution would be adding a hook in the plugin to decide whether or not
> > to end the probing process after each port probe finishes.  How do you
> > think?
>
> Yes, that second option would be cleaner. What I don't know is the
> outcome of that generic method. This is, should the method just disable
> the minimum probing time? Or should it actually ignore further ongoing
> probings (e.g. serial ports being probed for AT or QCDM) once we get the
> minimum set of ports we wanted?

One problem is how the plugin knows that specific ports are primary or
secondary or what.  You typically don't get this information without
tagging specific USB interface numbers like Windows does, and even then
we have had cases of this changing on firmware upgrades.  So I'm not
sure the generic  method should be too aggressive here, instead I think
it should be opt-in on a per-plugin or per-device basis.

Only if you're 100% sure about the layout of a specific modem (and we
have to be very careful that the USB VID/PID aren't re-used bewteen
different devices like ZTE and Huawei often do) should the current probe
process be bypassed.

Dan