RE: ATA driver races with interrupts

I wrote:

> Unfortunately the machine disconnected one of the SATA discs 
> earlier today. It did so out-of-the-blue, because there was
> no activity at all on either of the two discs other than the
> SMART monitor.
> 
> Aug  5 11:45:47 fortify kernel: ad20: WARNING - removed from 
> configuration
> Aug  5 11:45:47 fortify kernel: ata10-master: FAILURE - 
> unknown CMD (0xb0)
> timed out
> Aug  5 11:45:47 fortify smartd[882]: Device: /dev/ad20, not 
> capable of SMART
> self-check
[...]
> I have switched back to the patch from Ville-Pertti that
> serializes the controller for now, to see if that is more
> stable.

After 3+ days of uptime, including continuous SMART monitoring (which
without patch triggers an immediate disconnect, and with Sörens patch
triggered a disconnect after ~16 hours) and a fair amount of disc activity
on both channels it looks like maybe the serialization patch from
Ville-Pertti is enough to make my SATA controller work properly. Of course,
it also slows things down, but right now that is better than the
alternative.

Sören, if you have any other patches you would like me to test just let me
know.

/Daniel Eriksson