[PATCH] sata_sis: fix flags handling for the secondary port

sis_init_one() modifies probe_ent->port_flags after allocating and
initializing it using ata_pci_init_native_mode().  This makes port_flags
for the secondary port (probe_ent->pinfo2->flags) go out of sync resulting
in misdetection of device due to incorrectly initialized SCR access flag.

This patch make probe_ent alloc/init happen after the final port flags
value is determined.  This is fragile but probe_ent and all the related
mess are scheduled to go away soon for exactly this reason.  We just need
to hold everything together till then.

This has been spotted and diagnosed and tested by Patrick McHardy.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Patric McHardy <kaber@trash.net>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/ata/sata_sis.c

@@ -240,7 +240,7 @@ static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ata_probe_ent *probe_ent = NULL;
 	int rc;
 	u32 genctl;
-	struct ata_port_info *ppi[2];
+	struct ata_port_info pi = sis_port_info, *ppi[2] = { &pi, &pi };
 	int pci_dev_busy = 0;
 	u8 pmr;
 	u8 port2_start;
@@ -265,27 +265,20 @@ static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (rc)
 		goto err_out_regions;
 
-	ppi[0] = ppi[1] = &sis_port_info;
-	probe_ent = ata_pci_init_native_mode(pdev, ppi, ATA_PORT_PRIMARY | ATA_PORT_SECONDARY);
-	if (!probe_ent) {
-		rc = -ENOMEM;
-		goto err_out_regions;
-	}
-
 	/* check and see if the SCRs are in IO space or PCI cfg space */
 	pci_read_config_dword(pdev, SIS_GENCTL, &genctl);
 	if ((genctl & GENCTL_IOMAPPED_SCR) == 0)
-		probe_ent->port_flags |= SIS_FLAG_CFGSCR;
+		pi.flags |= SIS_FLAG_CFGSCR;
 
 	/* if hardware thinks SCRs are in IO space, but there are
 	 * no IO resources assigned, change to PCI cfg space.
 	 */
-	if ((!(probe_ent->port_flags & SIS_FLAG_CFGSCR)) &&
+	if ((!(pi.flags & SIS_FLAG_CFGSCR)) &&
 	    ((pci_resource_start(pdev, SIS_SCR_PCI_BAR) == 0) ||
 	     (pci_resource_len(pdev, SIS_SCR_PCI_BAR) < 128))) {
 		genctl &= ~GENCTL_IOMAPPED_SCR;
 		pci_write_config_dword(pdev, SIS_GENCTL, genctl);
-		probe_ent->port_flags |= SIS_FLAG_CFGSCR;
+		pi.flags |= SIS_FLAG_CFGSCR;
 	}
 
 	pci_read_config_byte(pdev, SIS_PMR, &pmr);
@@ -306,6 +299,12 @@ static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 		port2_start = 0x20;
 	}
 
+	probe_ent = ata_pci_init_native_mode(pdev, ppi, ATA_PORT_PRIMARY | ATA_PORT_SECONDARY);
+	if (!probe_ent) {
+		rc = -ENOMEM;
+		goto err_out_regions;
+	}
+
 	if (!(probe_ent->port_flags & SIS_FLAG_CFGSCR)) {
 		probe_ent->port[0].scr_addr =
 			pci_resource_start(pdev, SIS_SCR_PCI_BAR);