Here is the cleaned up patch (as you suggested) that enables ata_piix
to work in RAID mode on ICH6R.  I tested it and it seems to behave
correctly

in all the modes---sees all 4 disks in IDE and RAID modes, doesn't
see any in Compatibility mode (which is right, because only two are
available and the regular IDE driver has picked them up already).


Change description:  only test for PCI IDE legacy mode, via the
PCI programming interface register, if the PCI device is of class
PCI_CLASS_STORAGE_IDE.
Signed-off-by: Martins Krikis <mkrikis@yahoo.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>