suspend and docking

[Kelsey Jordahl <kels@mbari.org>]

I have a Fujitsu 656tx laptop that I have been happily running Linux
on for over a year and a half.  One thing I have never been able to do 
with it to my satisfaction is "warm docking", in which the computer is 
taken off or placed on its docking station while in suspend mode.  I
think that under Windows this machine can do "hot docking" as well,
where the machine need not be suspended before docking/undocking.
That doesn't bother me, warm docking is fine if I can get it working.

I wonder if anyone else has solved this problem, either with the same
type of hardware or a similar docking station?  The problem is
recognizing and using the docking station hardware when available.  It 
seems to work fine going from a docked to an undocked state, but going 
back to the docking station after having been undocked does not work.
A reboot is always required to go back to the docking station.

A similar problem happens while suspending while in the docking
station, if nothing is done then networking through eth0 is lost.  I
was able to fix this problem by adding a script to /etc/apm/event.d
to take the network down on suspend and bring it back on resume, like
this:

 #!/bin/sh
 # stop/start networking for resuming from sleep
 # Kelsey Jordahl 8/9/00

 if [ "$1" = suspend ]; then
    /etc/init.d/dhcpcd stop
    /sbin/ifconfig eth0 down
 elif [ "$1" = resume ]; then
    /sbin/ifconfig eth0 up
    /etc/init.d/dhcpcd start
 fi

This works (more or less) while remaining in the docking station.  I
had hoped it would let me dock/undock as well, but it seems not to be
able to bring the network back up on returning to the dock once it has
resumed without the docking station (and thus the ethernet card).  A
further problem with this script seems to be that after a few
suspend/resume cycles, even while undocked, it will eventually ignore
a command to suspend.  Perhaps the script should recognize that it is
undocked and not try to bring up ethernet, but I'm not sure how to do
this automatically.

I've tried manually unloading and loading the tulip card module as
well to try to force recognition of the hardware after resume, but I
haven't got this to work.

Any ideas on how to properly recognize docking station hardware after
a resume without rebooting?

A few more details: Fujitsu 656tx with docking station containing 16x
IDE CD-ROM drive, 1.44MB floppy drive, ports, speakers and Digital
DS21143 Tulip ethernet card.  Currently running Anthony Towns'
"testing" Debian distribution, although the problems seemed the same
while running RedHat 5.2 or Debian potato.

Thanks,
Kelsey

-- 
Kelsey Jordahl
Monterey Bay Aquarium Research Institute