[PATCH] libata-sff: Allow for wacky systems

There are some Linux supported platforms that simply cannot hit the low
I/O addresses used by ATA legacy mode PCI mappings. These platforms have
a window for PCI space that is fixed by the board logic and doesn't
include the neccessary locations.

Provide a config option so that such platforms faced with a controller
that they cannot support simply error it and punt

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 06daaa3736a2..7645f2b30ccf 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -981,6 +981,15 @@ int ata_pci_init_one (struct pci_dev *pdev, struct ata_port_info **port_info,
                 mask = (1 << 2) | (1 << 0);
                 if ((tmp8 & mask) != mask)
                         legacy_mode = (1 << 3);
+#if defined(CONFIG_NO_ATA_LEGACY)
+                /* Some platforms with PCI limits cannot address compat
+                   port space. In that case we punt if their firmware has
+                   left a device in compatibility mode */
+                if (legacy_mode) {
+                        printk(KERN_ERR "ata: Compatibility mode ATA is not supported on this platform, skipping.\n");
+                        return -EOPNOTSUPP;
+                }
+#endif
         }
 
         rc = pci_request_regions(pdev, DRV_NAME);