ifdown/ifup eth0 mini2440

I am able to do ifdown eth0 but when trying to bring it back up I don't
re-able the connection.

I have tried:
ifup -f eth0  and
ifconfig -f eth0

ifconfig says that eth0 is up even just doing ifup eth0, I can not ping the
mini2440.  I have checked /var/run/ifstate for the correct entries.

I am not sure if this happened since I got the wireless working on it.  I
have determined that I need to comment out the interface I do not want to
use in /etc/network/interfaces before trying to use the one I want.

Perhaps this is a hotplugging issue or maybe this problem is due to having
both interfaces as static.

Any ideas?  Even if someone could verify that on a standard FriendlyArm
2.6.32.2 install that things work properly would be helpful.

Thanks.

Argh ... after a few days messing around with this all it takes is posting
a question to get it working!

Latest "theory" is that having wlan0 listed in /etc/network/interfaces
seems to be the reason eth0 is mis-behaving when trying to bring it back
up.

Off to read up about hot-plugging.

When you re-enable the eth0 interface, is it really configured in the same
way than before?
Run an ifconfig, remember the settings, ifdown the interface, ifup it again
and then run ifconfig again to see, if the new settings are the same. If
they are the same, 'cat' the "proc/interrupts" file while you ping your
Mini2440 from your host and see, if the interrupts for the network device
increase. It not, it should be a regression and we should have a look into
the driver. Which kernel revision do you currently run on your Mini2440?

Subsequently this problem only seemed to appear when I was using a Ethernet
to USB adapter.  Checked again this morning and I couldn't even get that
adapter to work on boot-up.

Doing cat /proc/interrupts confirms that nothing is even getting to the
mini2440.

New "theory" is that doing an ifdown eth0 on the mini2440 (when I could get
an ethernet connection) upsets the ethernet to USB adapter (Digitus).

I am still running 3.7 Pengutronix

Thanks for the troubleshooting tip.

Cheers,
davef