ATA driver races with interrupts

[Daniel Eriksson]

By the way, I've ordered a Promise SATA150 TX4 that will show up in ~2
weeks. That should take care of my problems with the onboard SATA. However,
until then I'd be happy to try to help narrow this down (with the
understanding that I'm doing this on a production server, so uptime and data
integrity is important).

Let me know if there is anything else I should test, and I'll try to squeeze
some server downtime into the schedule.

/Daniel Eriksson