fix/workaround for usb probe lockups on nForce2 mbs

[Brandon Fosdick]

Andrew Atrens wrote:
> 
> All,
> 
> The attached patch fixes the boot lockups I've been experiencing on my 
> nForce2 (A7N8X-Deluxe) motherboards when usb devices are on the bus at 
> boot time.
> 
> Looks like something in usb_explore is (inadvertently?) enabling 
> interrupts if it detects a device on a port. The fix is, during hub 
> attach, to not assume that interrupts are off when we access the hub in 
> 'polling' mode.
> 
> Not sure if this is a fix or a workaround. I'll leave that to the usb 
> gods to decide ...
> 
> At any rate, I'd appreciate some feedback ... nForce2 users, does this 
> work for you ?

It worked for me. I had to do a full buildworld, just doing buildkernel 
wasn't enough. Thanks for the patch.

At this point I'm not sure if I want to try the patch from Ian Dowse 
since its working now and my USB hub is showing up as an OHCI.