Pack of CAM improvements

[Alexander Motin]

James R. Van Artsdalen wrote:
> At some point I hope to add support for staggered spin-ups, perhaps a
> loader.conf setting for people with more than 20-30 disks.  At the
> 100-120 disk level it seems unlikely that any reasonable fixed delay
> would be reasonable.

I've just added Power Up In Stand-by (PUIS) feature support into CAM ATA
in HEAD. It is one of the ways to implement staggered spin-up for ATA
devices. Now CAM will spin-up no more then 4 of such devices at a time.
Another way, based on SATA hard-reset sequence, is more complicated
(especially when port multipliers used) and not supported yet.

-- 
Alexander Motin