PCI: shpchp: Rely on previous _OSC results

If _OSC exists, we evaluated it when adding the ACPI host bridge, and we
requested SHPC control if the SHPC driver is present.  Use the result of
that _OSC evaluation instead of evaluating it again.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: split to separate patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index c9816166978ee41829430270dae15fd1eca9c9f9..65cc5042489ad540599a05de714c59e2ebf719f6 100644 (file)
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -69,16 +69,12 @@ static acpi_status acpi_run_oshp(acpi_handle handle)
  */
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
 {
+       const struct pci_host_bridge *host;
+       const struct acpi_pci_root *root;
        acpi_status status;
        acpi_handle chandle, handle;
        struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
 
-       flags &= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
-       if (!flags) {
-               err("Invalid flags %u specified!\n", flags);
-               return -EINVAL;
-       }
-
        /*
         * Per PCI firmware specification, we should run the ACPI _OSC
         * method to get control of hotplug hardware before using it. If
@@ -88,19 +84,14 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
         * OSHP within the scope of the hotplug controller and its parents,
         * up to the host bridge under which this controller exists.
         */
-       handle = acpi_find_root_bridge_handle(pdev);
-       if (handle) {
-               acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
-               dbg("Trying to get hotplug control for %s\n",
-                               (char *)string.pointer);
-               status = acpi_pci_osc_control_set(handle, &flags, flags);
-               if (ACPI_SUCCESS(status))
-                       goto got_one;
-               if (status == AE_SUPPORT)
-                       goto no_control;
-               kfree(string.pointer);
-               string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
-       }
+       host = pci_find_host_bridge(pdev->bus);
+       if (host->native_shpc_hotplug)
+               return 0;
+
+       /* If _OSC exists, we should not evaluate OSHP */
+       root = acpi_pci_find_root(ACPI_HANDLE(&host->dev));
+       if (root->osc_support_set)
+               goto no_control;
 
        handle = ACPI_HANDLE(&pdev->dev);
        if (!handle) {