5 files changed, 49 insertions, 30 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 77cd19697b1e..c34713112520 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -374,21 +374,32 @@ out:
 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 
 /**
- * acpi_pci_osc_control_set - commit requested control to Firmware
- * @handle: acpi_handle for the target ACPI object
- * @flags: driver's requested control bits
+ * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
+ * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
+ * @mask: Mask of _OSC bits to request control of, place to store control mask.
+ * @req: Mask of _OSC bits the control of is essential to the caller.
  *
- * Attempt to take control from Firmware on requested control bits.
+ * Run _OSC query for @mask and if that is successful, compare the returned
+ * mask of control bits with @req.  If all of the @req bits are set in the
+ * returned mask, run _OSC request for it.
+ *
+ * The variable at the @mask address may be modified regardless of whether or
+ * not the function returns success.  On success it will contain the mask of
+ * _OSC bits the BIOS has granted control of, but its contents are meaningless
+ * on failure.
  **/
-acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
+acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 {
+        struct acpi_pci_root *root;
         acpi_status status;
-        u32 control_req, result, capbuf[3];
+        u32 ctrl, capbuf[3];
         acpi_handle tmp;
-        struct acpi_pci_root *root;
 
-        control_req = (flags & OSC_PCI_CONTROL_MASKS);
-        if (!control_req)
+        if (!mask)
+                return AE_BAD_PARAMETER;
+
+        ctrl = *mask & OSC_PCI_CONTROL_MASKS;
+        if ((ctrl & req) != req)
                 return AE_TYPE;
 
         root = acpi_pci_find_root(handle);
@@ -400,27 +411,33 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
                 return status;
 
         mutex_lock(&osc_lock);
+
+        *mask = ctrl | root->osc_control_set;
         /* No need to evaluate _OSC if the control was already granted. */
-        if ((root->osc_control_set & control_req) == control_req)
+        if ((root->osc_control_set & ctrl) == ctrl)
                 goto out;
 
-        /* Need to query controls first before requesting them */
-        flags = control_req;
-        status = acpi_pci_query_osc(root, root->osc_support_set, &flags);
-        if (ACPI_FAILURE(status))
-                goto out;
+        /* Need to check the available controls bits before requesting them. */
+        while (*mask) {
+                status = acpi_pci_query_osc(root, root->osc_support_set, mask);
+                if (ACPI_FAILURE(status))
+                        goto out;
+                if (ctrl == *mask)
+                        break;
+                ctrl = *mask;
+        }
 
-        if (flags != control_req) {
+        if ((ctrl & req) != req) {
                 status = AE_SUPPORT;
                 goto out;
         }
 
         capbuf[OSC_QUERY_TYPE] = 0;
         capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
-        capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
-        status = acpi_pci_run_osc(handle, capbuf, &result);
+        capbuf[OSC_CONTROL_TYPE] = ctrl;
+        status = acpi_pci_run_osc(handle, capbuf, mask);
         if (ACPI_SUCCESS(status))
-                root->osc_control_set = result;
+                root->osc_control_set = *mask;
 out:
         mutex_unlock(&osc_lock);
         return status;
@@ -551,8 +568,8 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         if (flags != base_flags)
                 acpi_pci_osc_support(root, flags);
 
-        status = acpi_pci_osc_control_set(root->device->handle,
-                                          OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+        flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
+        status = acpi_pci_osc_control_set(root->device->handle, &flags, flags);
 
         if (ACPI_FAILURE(status)) {
                 printk(KERN_INFO "Unable to assume PCIe control: Disabling ASPM\n");
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index 45fcc1e96df9..3d93d529a7bd 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -360,7 +360,7 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
                 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);
+                status = acpi_pci_osc_control_set(handle, &flags, flags);
                 if (ACPI_SUCCESS(status))
                         goto got_one;
                 if (status == AE_SUPPORT)
diff --git a/drivers/pci/pcie/aer/aerdrv_acpi.c b/drivers/pci/pcie/aer/aerdrv_acpi.c
index f278d7b0d95d..3a276a0cea93 100644
--- a/drivers/pci/pcie/aer/aerdrv_acpi.c
+++ b/drivers/pci/pcie/aer/aerdrv_acpi.c
@@ -39,9 +39,9 @@ int aer_osc_setup(struct pcie_device *pciedev)
 
         handle = acpi_find_root_bridge_handle(pdev);
         if (handle) {
-                status = acpi_pci_osc_control_set(handle,
-                                        OSC_PCI_EXPRESS_AER_CONTROL |
-                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+                u32 flags = OSC_PCI_EXPRESS_AER_CONTROL |
+                                OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
+                status = acpi_pci_osc_control_set(handle, &flags, flags);
         }
 
         if (ACPI_FAILURE(status)) {
diff --git a/drivers/pci/pcie/pme/pcie_pme_acpi.c b/drivers/pci/pcie/pme/pcie_pme_acpi.c
index 83ab2287ae3f..be20222b12d3 100644
--- a/drivers/pci/pcie/pme/pcie_pme_acpi.c
+++ b/drivers/pci/pcie/pme/pcie_pme_acpi.c
@@ -28,6 +28,7 @@ int pcie_pme_acpi_setup(struct pcie_device *srv)
         acpi_status status = AE_NOT_FOUND;
         struct pci_dev *port = srv->port;
         acpi_handle handle;
+        u32 flags;
         int error = 0;
 
         if (acpi_pci_disabled)
@@ -39,9 +40,10 @@ int pcie_pme_acpi_setup(struct pcie_device *srv)
         if (!handle)
                 return -EINVAL;
 
-        status = acpi_pci_osc_control_set(handle,
-                        OSC_PCI_EXPRESS_PME_CONTROL |
-                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
+        flags = OSC_PCI_EXPRESS_PME_CONTROL |
+                OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
+
+        status = acpi_pci_osc_control_set(handle, &flags, flags);
         if (ACPI_FAILURE(status)) {
                 dev_info(&port->dev,
                         "Failed to receive control of PCIe PME service: %s\n",
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ccf94dc5acdf..c227757feb06 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -304,8 +304,8 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
                                 OSC_PCI_EXPRESS_PME_CONTROL |           \
                                 OSC_PCI_EXPRESS_AER_CONTROL |           \
                                 OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL)
-
-extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags);
+extern acpi_status acpi_pci_osc_control_set(acpi_handle handle,
+                                             u32 *mask, u32 req);
 extern void acpi_early_init(void);
 
 #else   /* !CONFIG_ACPI */