Disable root mount waiting for USB

[Sam Leffler]

Ed Schouten wrote:
> * Kamigishi Rei <spambox at haruhiism.net> wrote:
>> Ed Schouten wrote:
>>>> Is there a way (loader tunable or kernel config) to disable the root
>>>> mount waiting for USB buses and devices and make it behave just like
>>>> in the first days of the new USB stack ?
>>> Why can't we just wait until the device node that should be mounted is
>>> available?
>> We're talking about this USB delay which appears almost always
>> during the initialization of the USB stack.
>>
>> Jul 19 07:21:34 ameagari kernel: Root mount waiting for: usbus7 usbus3
>> Jul 19 07:21:34 ameagari kernel: Trying to mount root from ufs:/dev/ad10s1a
>>
>> In this case, the delay is insignificant, however with some systems
>> this can take up to 10 seconds.
>> And we don't even need to wait for USB bus because the root
>> filesystem is on an ATA hard disk.
> 
> So that's why I'm saying: why can't we just wait until the device node
> that should be mounted is available?
> 

Talk to Scott Long how to correctly fix this issue.  Andrew Thompson 
tried but his attempt was backed out as incorrect.  So far as I know 
noone has stepped up to address the real problem here.

	Sam