[PATCH 1/7] ACPI / PCI: Make acpi_pci_run_osc() use capbuf to return the result

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rjw@sisk.pl>

There is no reason why acpi_pci_run_osc() should use a separate
argument to return the _OSC result, since there is a place for it
in the buffer passed via capbuf, as none of the callers needs to
preserve the original contents of that buffer, so drop the third
argument of acpi_pci_run_osc() and modify the callers accordingly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/acpi/pci_root.c |   17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

Index: linux-2.6/drivers/acpi/pci_root.c
===================================================================
--- linux-2.6.orig/drivers/acpi/pci_root.c
+++ linux-2.6/drivers/acpi/pci_root.c
@@ -206,8 +206,7 @@ static void acpi_pci_bridge_scan(struct 
 
 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 
-static acpi_status acpi_pci_run_osc(acpi_handle handle,
-				    const u32 *capbuf, u32 *retval)
+static acpi_status acpi_pci_run_osc(acpi_handle handle, u32 *capbuf)
 {
 	struct acpi_osc_context context = {
 		.uuid_str = pci_osc_uuid_str,
@@ -219,7 +218,7 @@ static acpi_status acpi_pci_run_osc(acpi
 
 	status = acpi_run_osc(handle, &context);
 	if (ACPI_SUCCESS(status)) {
-		*retval = *((u32 *)(context.ret.pointer + 8));
+		capbuf[OSC_CONTROL_TYPE] = ((u32 *)context.ret.pointer)[2];
 		kfree(context.ret.pointer);
 	}
 	return status;
@@ -228,7 +227,7 @@ static acpi_status acpi_pci_run_osc(acpi
 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
 {
 	acpi_status status;
-	u32 support_set, result, capbuf[3];
+	u32 support_set, capbuf[3];
 
 	/* do _OSC query for all possible controls */
 	support_set = root->osc_support_set | (flags & OSC_PCI_SUPPORT_MASKS);
@@ -236,10 +235,10 @@ static acpi_status acpi_pci_query_osc(st
 	capbuf[OSC_SUPPORT_TYPE] = support_set;
 	capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
 
-	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
+	status = acpi_pci_run_osc(root->device->handle, capbuf);
 	if (ACPI_SUCCESS(status)) {
 		root->osc_support_set = support_set;
-		root->osc_control_qry = result;
+		root->osc_control_qry = capbuf[OSC_CONTROL_TYPE];
 		root->osc_queried = 1;
 	}
 	return status;
@@ -373,7 +372,7 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
 {
 	acpi_status status;
-	u32 control_req, result, capbuf[3];
+	u32 control_req, capbuf[3];
 	acpi_handle tmp;
 	struct acpi_pci_root *root;
 
@@ -410,9 +409,9 @@ acpi_status acpi_pci_osc_control_set(acp
 	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);
+	status = acpi_pci_run_osc(handle, capbuf);
 	if (ACPI_SUCCESS(status))
-		root->osc_control_set = result;
+		root->osc_control_set = capbuf[OSC_CONTROL_TYPE];
 out:
 	mutex_unlock(&osc_lock);
 	return status;