SATA DMA errors on second ICH10 bus

[Dylan Alex Simon]

> That advice seems to be particularly valuable given the
> current firmware problems that particular Seagate disks
> are exhibiting.

I've confirmed with Seagate and others that the firmware these disks already
have (CC1F) is not affected by the firmware problems.  The instability (as
described in kern/130726) continues with a kernel from today.  I've traced it
down to exclusively and reliably being caused by access to disks on multiple
channels simultaneously (access to any pair of disks on the same channel works
fine).  If anyone has any suggestions or any other data I should collect let
me know as I will have to put these machines into production shortly (without
freebsd unfortunately).

:-Dylan