wm(4) issue/question

[Chris Ross <cross+netbsd%distal.com@localhost>]

  First of all, I want to point out that I don't presume this is  
necessarily related to the wm(4) driver.  But, it does involve one,  
and I have an issue I don't understand.  I'm hoping someone closer to  
the wm sources might be able to assist me.

  I have an i386 router with a fiber Intel GigE card ("Intel i82543GC  
1000BASE-X Ethernet, rev. 2").  This is connected to a SX GBIC on a  
switch, and I'm running numerous 802.1q VLANs across it.  This is all  
working fine.

  I am trying to replace the 10/100 switches (with Gigabit GBIC  
ports) with full gigabit switches.  I have a Dell 2724 with SX SFP's  
in it, and I tried connecting the i386 with wm(4) to one of them last  
night, after trunking that new switch into the existing fabric.

  I was getting 80% or more packet loss between my desktop and the  
router (via one of it's many VLAN interfaces).  I was, throughout this  
attempt, seeing the following type message on the console of the router:

wm0: device timeout (txfree 255 txsfree 63 txnext 6)
wm0: symbol error
wm0: device timeout (txfree 252 txsfree 62 txnext 64)
wm0: device timeout (txfree 252 txsfree 62 txnext 27)
wm0: device timeout (txfree 227 txsfree 41 txnext 121)
wm0: device timeout (txfree 249 txsfree 59 txnext 28)
wm0: device timeout (txfree 252 txsfree 62 txnext 10)
wm0: device timeout (txfree 255 txsfree 63 txnext 179)

  So, my first question is, does anyone more familiar with the wm(4)  
driver have any sense what that message means, and what else I should  
look at/into to figure out what sort of problem this is?

  Note, that I didn't try to pull everything into the new  
infrastructure cold, so things like ARP caches and such may still be  
involved in the issue(s).  But, this doesn't look like that sort of  
problem to me.

  Thanks for any pointers or ideas anyone has...

                          - Chris