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>

1 files changed, 29 insertions, 12 deletions

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 93e37f0666ab..bd831970f00b 100644
--- 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);