USB issues with Aladdin M5237

[Cliff L. Biffle]

I'm having issues with my laptop's USB under -current (snapshot as of today).  
The controller has never worked in FreeBSD (4.x or 5.x), but works fine under 
Knoppix.

I've found messages to mobile@ dating back a couple of years with people 
getting my exact symptoms on the same controller -- but there are also 
messages from folks for whom it works fine.

The symptoms: when I attach a device, nothing happens.  Shortly thereafter (if 
I'm lucky) it will output 'uhub0: device problem, disabling port 1.'
If I plug in a bus-powered device with a power indicator (such as one of my 
hubs), the device acts like it's getting some power, but doesn't work 
properly.  (The hub in particular turns its power light on but won't power 
the ports up.)  Again, this works fine in Knoppix.

With hw.usb.ohci.debug=1 and hw.usb.debug=1, I get the following output:

usbd_new_device: addr=2, getting first desc failed
uhub_explore: usb_new_device failed, error=TIMEOUT
uhub0: device problem, disabling port 1

The OHCI probes correctly at boot, at least from what I can tell in the dmesg.  
Relevant lines:

ohci0: <AcerLabs M5237 (Aladdin-V) USB controller> mem 0xfedee000-0xfedeefff 
irq 9 at device 19.0 on pci0
usb0: OHCI version 1.0, legacy support
usb0: <AcerLabs M5237 (Aladdin-V) USB controller> on ohci0
usb0: USB revision 1.0
uhub0: AcerLabs OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered

HELP! :-)  I'm more than willing to muck around in the OHCI sources, if 
someone can point me at a place to start -- I've found the USB stack in 
general to be, well, underdocumented. :-)  I've already requested a datasheet 
on the part from Aladdin so I can double-check if perhaps my BIOS isn't 
properly initializing the part.

Suggestions?

-Cliff L. Biffle