pata_atiixp: Don't use unconnected secondary port on SB600/SB700

The SB600 and SB700 southbridge chips from ATI/AMD only have
connections for the primary IDE port. As these chips have unique
pci device ID's use these to mark the secondary port as 'dummy'
Signed-off-by: NDarren Stevens <darren@stevens-zone.net>
Signed-off-by: NTejun Heo <tj@kernel.org>

drivers/ata/pata_atiixp.c

@@ -278,6 +278,11 @@ static int atiixp_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	};
 	const struct ata_port_info *ppi[] = { &info, &info };
 
+	/* SB600/700 don't have secondary port wired */
+	if ((pdev->device == PCI_DEVICE_ID_ATI_IXP600_IDE) ||
+		(pdev->device == PCI_DEVICE_ID_ATI_IXP700_IDE))
+		ppi[1] = &ata_dummy_port_info;
+
 	return ata_pci_bmdma_init_one(pdev, ppi, &atiixp_sht, NULL,
 				      ATA_HOST_PARALLEL_SCAN);
 }