ATA driver races with interrupts

[Ville-Pertti Keinonen]

Søren Schmidt wrote:

> Reliable solutions needs reliable HW, we can narrow down the race 
> window here, but without HW support we cannot close it completely 
> unless we serialises access to the channels (what lots of OS's does 
> btw)..

For now, I moved my SATA disks to the Promise controller, which seems to 
work with an unpatched -current.

If serialization is the only reliable solution, shouldn't it be enabled 
for all controllers with multiple channels on the same irq that use 
ata_generic_intr?  It isn't going to hurt performance when only using 
one channel, and when using multiple channels...currently it's pretty 
much guaranteed to blow up.