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

[Daenyth Blank <daenyth gmail com>]

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.