usb ohci lockup during enumeration on 5.0?

[Gregory P. Smith]

I have an "old" Toshiba Portege 320CT laptop (266Mhz pentium+mmx)
running REL_ENG_5_0.  It has an NEC OHCI usb controller.

When I plug any usb device in (i'm using a mouse for simple testing)
the system locks up such that no console processes respond but i can
still switch virtual consoles using the alt-Fn.

I assume this means that interrupts/bottom half code is still working
but that top level processes are no longer being scheduled?.

Enabling all of the usb debug values in sysctl beforehand does not produce
any output (nor does usbd -d -v -v produce any when i plug something in).

Any suggestions?  Is anyone else having usb ohci problems with 5.0?

I'm recompiling the kernel with DDB as I write this.

tia,
Greg