OK after a reboot with the same BIOS it wants to work this time.

this is really weird. I have a different set of interrupts in use,  
but the usb controllers report that they are on the same ones as  
before. Just ehci getting a mapping seems to make things almost work  
right.

Before it was 6,4,16,22,14,20
Now it is 6,4,16,21,22,18,23,14,20

And, I never saw this in usbdebug messages when nothing was responding:

usb_schedsoftintr: polling=0

If I hop into ddb it becomes

usb_schedsoftinr: polling=1

I also still sometimes see that when I unplug a device and plug it  
back in, nothing gets noticed until I unplug a working device  
somewhere else on the chain, even when its attached to a hub, and  
then the device I plugged into the root gets noticed and configured.

So it looks like soft interrupts might be part of the issue, but I'm  
still clueless as to where to go next or what this ehci_sync_hc:  
tsleep=35 means.



This is the new list with a working device on every hub:

-bash-3.00# vmstat -i
interrupt                                     total     rate
cpu0 softclock                               202009      100
cpu0 softnet                                   4625        2
cpu0 softserial                                  17        0
cpu0 timer                                   202187      100
cpu0 FPU synch IPI                                2        0
cpu0 TLB shootdown IPI                         1200        0
cpu1 timer                                   201185       99
cpu1 timeset IPI                               2011        0
cpu1 FPU flush IPI                                2        0
cpu1 FPU synch IPI                                2        0
cpu1 TLB shootdown IPI                         4047        2
ioapic0 pin 6                                     1        0
ioapic0 pin 4                                    21        0
ioapic0 pin 16                                 5653        2
ioapic0 pin 21                                  244        0
ioapic0 pin 22                                  446        0
ioapic0 pin 18                                   26        0
ioapic0 pin 23                                    7        0
ioapic0 pin 14                                   35        0
ioapic0 pin 20                                 1698        0
Total                                        625418      310


> -bash-3.00# vmstat -i
> interrupt                                     total     rate
> cpu0 softclock                                25587      105
> cpu0 softnet                                    310        1
> cpu0 softserial                                   1        0
> cpu0 timer                                    25764      106
> cpu0 FPU flush IPI                                2        0
> cpu0 FPU synch IPI                                1        0
> cpu0 TLB shootdown IPI                          582        2
> cpu1 timer                                    24334      100
> cpu1 timeset IPI                                243        1
> cpu1 FPU synch IPI                                4        0
> cpu1 TLB shootdown IPI                         1113        4
> ioapic0 pin 6                                     1        0
> ioapic0 pin 4                                     1        0
> ioapic0 pin 16                                  285        1
> ioapic0 pin 22                                  103        0
> ioapic0 pin 14                                   35        0
> ioapic0 pin 20                                 1146        4
> Total                                         79512      327