Ok I have isolated this to new locking in the sysfs file read code.
This seems to be necessary locking as there was a chance that the values
being read could be freed underneath us.  Contention between usb_id and
khubd (presumably) scanning the hub leads to extended waits usb_id
trying to aquire the usb device semaphore.  We could probabally fix this
by converting the update of these values to rcu but that would require
fixing all of those sharing the sysfs code, which appears to be all usb
devices.

So the key question is, Is the delay on usb_id actually causing an issue
here now that we are not blocking on it?

-- 
[2.6.32-11 regression] 5 second delay on early boot during usb_id
https://bugs.launchpad.net/bugs/510937
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