1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 642554b1b60c..5b38a026d122 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -31,6 +31,7 @@
 #include <linux/spinlock.h>
 #include <linux/pm.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
@@ -193,6 +194,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         unsigned long long value = 0;
         acpi_handle handle = NULL;
         struct acpi_device *child;
+        u32 flags, base_flags;
 
 
         if (!device)
@@ -210,6 +212,13 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 
         device->ops.bind = acpi_pci_bind;
 
+        /*
+         * All supported architectures that use ACPI have support for
+         * PCI domains, so we indicate this in _OSC support capabilities.
+         */
+        flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+        pci_acpi_osc_support(device->handle, flags);
+
         /* 
          * Segment
          * -------
@@ -335,6 +344,17 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         list_for_each_entry(child, &device->children, node)
                 acpi_pci_bridge_scan(child);
 
+        /* Indicate support for various _OSC capabilities. */
+        if (pci_ext_cfg_avail(root->bus->self))
+                flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
+        if (pcie_aspm_enabled())
+                flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
+                        OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
+        if (pci_msi_enabled())
+                flags |= OSC_MSI_SUPPORT;
+        if (flags != base_flags)
+                pci_acpi_osc_support(device->handle, flags);
+
       end:
         if (result) {
                 if (!list_empty(&root->node))