Re: Re-scanning for available devices/connections after failure

[Dan Williams <dcbw redhat com>]

On Thu, 2010-07-15 at 15:00 -0400, Daenyth Blank wrote:
> On Thu, Jul 15, 2010 at 16:45, Dan Williams <dcbw redhat com> wrote:
> > For 3G devices this could be a number of things.  If the device simply
> > isn't seen by NM, that means that ModemManager didn't successfully probe
> > the device.  So we need to look for it there.
> This sounds like the case some of the time
> 
> > If this happens when the device disconnects, it could be that the
> > device's firmware is crashing and its dropping off the USB bus.  That's
> > odd and indicates firmware problems, some of which we can work around in
> > ModemManager.  Other times the device is just screwed and needs a
> > firmware update.  If the device isn't recognized at *boot* time, that
> > could indicate either kernel problems, device problems, or possibly udev
> > issues.
> Sometimes it's recognized and others it's not. Is it possible that the
> device is left in some half-set state or is hanging and that prevents
> it from being probed?
> 
> > When the device isn't found, lets get some 'dmesg' output from the
> > kernel to see if the device is actually getting loaded correctly.  Also
> > see if the device's ports are present in /dev/.
> I don't have the output to hand, but I do remember checking and
> finding that the kernel did see it and the sierra driver was loaded
> for it. lsusb also showed it as present.

And there were /dev/ttyUSBx ports for the device?  If you can get it
into that state again, do this:

1) mv /usr/sbin/modem-manager /
2) killall -TERM modem-manager
3) /modem-manager --debug

and see what MM says.  When you're done,
mv /modem-manager /usr/sbin/modem-manager.

Dan