2 files changed, 38 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5dffcfefc3c7..61a56b100c62 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -633,6 +633,14 @@ running once the system is up.
         inport.irq=     [HW] Inport (ATI XL and Microsoft) busmouse driver
                         Format: <irq>
 
+        combined_mode=  [HW] control which driver uses IDE ports in combined
+                        mode: legacy IDE driver, libata, or both
+                        (in the libata case, libata.atapi_enabled=1 may be
+                        useful as well).  Note that using the ide or libata
+                        options may affect your device naming (e.g. by
+                        changing hdc to sdb).
+                        Format: combined (default), ide, or libata
+
         inttest=        [IA64]
 
         io7=            [HW] IO7 for Marvel based alpha systems
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 3a4f49f4effb..f28ebdd3958a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1098,6 +1098,23 @@ static void __init quirk_alder_ioapic(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_EESSC,      quirk_alder_ioapic );
 #endif
 
+enum ide_combined_type { COMBINED = 0, IDE = 1, LIBATA = 2 };
+/* Defaults to combined */
+static enum ide_combined_type combined_mode;
+
+static int __init combined_setup(char *str)
+{
+        if (!strncmp(str, "ide", 3))
+                combined_mode = IDE;
+        else if (!strncmp(str, "libata", 6))
+                combined_mode = LIBATA;
+        else /* "combined" or anything else defaults to old behavior */
+                combined_mode = COMBINED;
+
+        return 1;
+}
+__setup("combined_mode=", combined_setup);
+
 #ifdef CONFIG_SCSI_SATA_INTEL_COMBINED
 static void __devinit quirk_intel_ide_combined(struct pci_dev *pdev)
 {
@@ -1164,6 +1181,19 @@ static void __devinit quirk_intel_ide_combined(struct pci_dev *pdev)
         if (prog & comb)
                 return;
 
+        /* Don't reserve any so the IDE driver can get them (but only if
+         * combined_mode=ide).
+         */
+        if (combined_mode == IDE)
+                return;
+
+        /* Grab them both for libata if combined_mode=libata. */
+        if (combined_mode == LIBATA) {
+                request_region(0x1f0, 8, "libata");     /* port 0 */
+                request_region(0x170, 8, "libata");     /* port 1 */
+                return;
+        }
+
         /* SATA port is in legacy mode.  Reserve port so that
          * IDE driver does not attempt to use it.  If request_region
          * fails, it will be obvious at boot time, so we don't bother