Re: udev doesn't recognize my gsm dongle

[Dan Williams <dcbw redhat com>]

On Wed, 2010-02-03 at 10:52 +0100, Maxime Boure wrote:
> Hello again,
> 
> I corrected a part of my problem I don't need the LIBUDEV flag set to
> 0 anymore the problem was my udev package that was too old.... 
> 
> That is cleared out. 

Ok, great.

> But I still have a major problem. My GSM dongle will only be
> recognized by NetworkManager when I unplug/plug it when the board has
> loaded up.
> When I boot with the dongle plugged NM doesn't know it. What could be
> the problem ? 

Somewhere early in bootup, run 'udevadm control --log-priority=debug' to
get udev messages; this will give you a *lot* of logs about what udev is
running and when.  There may also be a way to just run udev initially
with this log level but I'm not sure what that is.

In NM 0.7.x, it works like this:

1) when the kernel finds a new tty, udev runs scripts including
nm-modem-probe
2) nm-modem-probe opens the port, detects capabilities, and sets some
udev environment variables
3) HAL is notified of the new serial port and emits a DeviceAdded signal
4) NM gets the DeviceAdded signal, and inspects the device for the udev
capabilities that nm-modem-probe added in step 2
5) if the tty has either CDMA or GSM capabilities, NM will manage it

so we need to find out where in this chain things are breaking down for
the bootup case.  A few things to try:

- get the detailed udev logs as described above

This will confirm that nm-modem-probe is actually being run when new
serial ports are detected.


- udevadm info --export-db

This will print out the udev database and let us see if the prober ran
successfully and detected any capabilities.


- lshal

This will let us know if HAL found the tty device correctly.


Dan

> I am thinking about the boot scheduling maybe...
> I begin with udev-->where the usb_modeswitch occurs
>                  dbus 
>                  hal 
>                  NetworkManager
> 
> I was thinking that the udev could have a different effect at boot
> comparatively to the unplug/plug when it has booted.
> 
> Am I missing something ? Any idea, working directions ?
> 
> Thanks a lot !