PCI: acpi_pcihp: run _OSC on a root bridge

_OSC should be ran on a root bridge instead of the device itself.  Do
this before touching OSHP since PCI fw specs states that _OSC should be
preferred over OSHP (however if the device has OSHP but not _OSC -- not
a root bridge -- it's not).

Cc: kristen.c.accardi@intel.com
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 93e37f0..bd83197 100644 (file)
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -382,7 +382,7 @@ EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
 {
        acpi_status status;
-       acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
+       acpi_handle chandle, handle;
        struct pci_dev *pdev = dev;
        struct pci_bus *parent;
        struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -399,10 +399,28 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
         * Per PCI firmware specification, we should run the ACPI _OSC
         * method to get control of hotplug hardware before using it. If
         * an _OSC is missing, we look for an OSHP to do the same thing.
-        * To handle different BIOS behavior, we look for _OSC and OSHP
-        * within the scope of the hotplug controller and its parents,
+        * To handle different BIOS behavior, we look for _OSC on a root
+        * bridge preferentially (according to PCI fw spec). Later for
+        * OSHP within the scope of the hotplug controller and its parents,
         * upto the host bridge under which this controller exists.
         */
+       while (pdev->bus->self)
+               pdev = pdev->bus->self;
+       handle = acpi_get_pci_rootbridge_handle(pci_domain_nr(pdev->bus),
+                       pdev->bus->number);
+       if (handle) {
+               acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+               dbg("Trying to get hotplug control for %s\n",
+                               (char *)string.pointer);
+               status = pci_osc_control_set(handle, flags);
+               if (ACPI_SUCCESS(status))
+                       goto got_one;
+               kfree(string.pointer);
+               string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
+       }
+
+       pdev = dev;
+       handle = DEVICE_ACPI_HANDLE(&dev->dev);
        while (!handle) {
                /*
                 * This hotplug controller was not listed in the ACPI name
@@ -427,15 +445,9 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
                acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
                dbg("Trying to get hotplug control for %s \n",
                    (char *)string.pointer);
-               status = pci_osc_control_set(handle, flags);
-               if (status == AE_NOT_FOUND)
-                       status = acpi_run_oshp(handle);
-               if (ACPI_SUCCESS(status)) {
-                       dbg("Gained control for hotplug HW for pci %s (%s)\n",
-                           pci_name(dev), (char *)string.pointer);
-                       kfree(string.pointer);
-                       return 0;
-               }
+               status = acpi_run_oshp(handle);
+               if (ACPI_SUCCESS(status))
+                       goto got_one;
                if (acpi_root_bridge(handle))
                        break;
                chandle = handle;
@@ -449,6 +461,11 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
 
        kfree(string.pointer);
        return -ENODEV;
+got_one:
+       dbg("Gained control for hotplug HW for pci %s (%s)\n", pci_name(dev),
+                       (char *)string.pointer);
+       kfree(string.pointer);
+       return 0;
 }
 EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);