Parallel enables occurring (when SIM PIN enabled)

[Dan Williams]

On Tue, 2017-04-25 at 10:32 +0200, Aleksander Morgado wrote:
> On Tue, Apr 25, 2017 at 10:20 AM, Colin Helliwell
> <colin.helliwell at ln-systems.com> wrote:
> > I've encountered a problem when using MM with Network Manager, when
> > the SIM PIN is enabled - in short it seems that MM is able to hit a
> > state where two 'enable' operations are happening in parallel, one
> > from unlocking the SIM and one from starting the 'simple connect'.
> > The detail and discussion so far has been over at http://www.mail-a
> > rchive.com/networkmanager-list at gnome.org/msg27008.html , but it
> > does seem to be an issue that essentially lies in MM.
> 
> Could you open a new bugreport in bugzilla and attach the relevant
> logs there as well? I believe we should track this.
> https://bugs.freedesktop.org/enter_bug.cgi?product=ModemManager

He originated this thread on the NM list (not sure if you saw it there)
and I diagnosed what was going on from an internal perspective.  It's a
race between the state change to ENABLING and the polkit auth stuff. 
We need to check right after the polkit auth that our state hasn't
changed already due to another request, and then do the right thing
(either return an error or allow the specific op to proceed).

Dan