Parallel enables occurring (when SIM PIN enabled)

[Dan Williams]

On Wed, 2017-04-26 at 12:12 +0200, Aleksander Morgado wrote:
> On Tue, Apr 25, 2017 at 4:43 PM, Dan Williams <dcbw at redhat.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.ma
> > > > il-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).
> 
> May have missed the email in the NM list. I saw the patch attached to
> the bugreport now, and my only concern was related to why a final
> state > ENABLED (e.g. registered or connected) would be treated as an
> error during the Enable() request.

Patch was more for confirmation/debugging than intended for commit.  We
can plug this particular hole with patches like that, but probably want
to figure out a more general strategy.  That said, I think this the
most likely case we'd encounter.

Dan