boot hang: "ata1: resetting devices .. done" (5.1-CURRENT, IBM T30)

[Soren Schmidt]

It seems Dan Nelson wrote:
> In the last episode (Oct 08), Robert Ferguson said:
> > I see this problem as well. I'm running on a T40, with a DVD/CDRW in  
> > the ultrabay, and -CURRENT as of this morning. At boot, it hangs  
> > immediately after
> > 
> > ad0: 35174MB <IC25N040ATCS05-0> [71465/16/63] at ata0-master UDMA100
> > ata1: resetting devices ..
> > done
> > 
> > Backing out the most recent checkin to sys/dev/ata/ata-queue.c (i.e.  
> > reverting to version 1.6) makes the problem go away.
> 
> I upgraded from an Oct 1 -> Oct 12 kernel and saw the same hang. 
> Backing out r1.6 fixed it for me too.

Hmm, that probably because I disabled the code that tries to deal with
lost interrupts (its no good and can easily panic your box, thats why).

We seem to be suffering from lost interrupts in -current for some time.
I can on at least one system here confirm that the interrupt does get
delivered from the device, but the ATA interrupt handler is newer called.
Where the interrupt gets lost and why is still beyond me, anyone that
can share some light on this is most welcome...

-Søren