I've just committed a batch of changes to make IDE and ATAPI probing
faster and more robust.  These changes defer probing for devices until
interrupts are enabled, removing the need for polling in most cases.

I have only been able to test this on PCs, some Macs and a SMDK2410
development board (with PCMCIA).  Hardware which has not been testing
at all includes:

acorn26
acorn32
amiga
atari
mac68k
playstation2
prep
i386: pciide at pnpbios

Of these, the two which are most sketchy are acorn32 (won't compile --
the code was weird enough that I didn't want to touch it) and
pciide_pnpbios (which will likely blow up).

Please test this code and notify me of any problems ASAP.  (If you
report a problem, including the ACTUAL MESSAGES you get from the
kernel, in addition to a description of why you think it's broken.)