[PATCH] ahci: Ensure that we don't grab both functions

When we force the chip into dual fn mode so we get PATA and AHCI we must
be sure we don't then do anything dumb like try and grab both with the AHCI
driver.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/scsi/ahci.c

@@ -1323,6 +1323,17 @@ static int ahci_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (!printed_version++)
 		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
 
+	/* JMicron-specific fixup: make sure we're in AHCI mode */
+	/* This is protected from races with ata_jmicron by the pci probe
+	   locking */
+	if (pdev->vendor == PCI_VENDOR_ID_JMICRON) {
+		/* AHCI enable, AHCI on function 0 */
+		pci_write_config_byte(pdev, 0x41, 0xa1);
+		/* Function 1 is the PATA controller */
+		if (PCI_FUNC(pdev->devfn))
+			return -ENODEV;
+	}
+
 	rc = pci_enable_device(pdev);
 	if (rc)
 		return rc;
@@ -1378,10 +1389,6 @@ static int ahci_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (have_msi)
 		hpriv->flags |= AHCI_FLAG_MSI;
 
-	/* JMicron-specific fixup: make sure we're in AHCI mode */
-	if (pdev->vendor == 0x197b)
-		pci_write_config_byte(pdev, 0x41, 0xa1);
-
 	/* initialize adapter */
 	rc = ahci_host_init(probe_ent);
 	if (rc)