[libata ata_piix] Fix ICH6/7 map value interpretation

The previous change failed to properly mask out unrelated bits, which
resulted in a failure to detect devices.

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c
index 19d8d4ba6a1e..2d984b090b23 100644
--- a/drivers/scsi/ata_piix.c
+++ b/drivers/scsi/ata_piix.c
@@ -713,7 +713,7 @@ static int piix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
                 pci_read_config_byte(pdev, ICH5_PMR, &tmp);
 
                 if (host_flags & PIIX_FLAG_COMBINED_ICH6) {
-                        switch (tmp) {
+                        switch (tmp & 0x3) {
                         case 0:
                                 break;
                         case 1: