ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argument

The callers of acpi_bus_add() usually assume that if it has
succeeded, then a struct acpi_device object has been attached to
the handle passed as the first argument.  Unfortunately, however,
this assumption is wrong, because acpi_bus_scan(), and acpi_bus_add()
too as a result, may return a pointer to a different struct
acpi_device object on success (it may be an object corresponding to
one of the descendant ACPI nodes in the namespace scope below that
handle).

For this reason, the callers of acpi_bus_add() who care about
whether or not a struct acpi_device object has been created for
its first argument need to check that using acpi_bus_get_device()
anyway, so the second argument of acpi_bus_add() is not really
useful for them.  The same observation applies to acpi_bus_scan()
executed directly from acpi_scan_init().

Therefore modify the relevant callers of acpi_bus_add() to check the
existence of the struct acpi_device in question with the help of
acpi_bus_get_device() and drop the no longer necessary second
argument of acpi_bus_add().  Accordingly, modify acpi_scan_init() to
use acpi_bus_get_device() to get acpi_root and drop the no longer
needed second argument of acpi_bus_scan().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

2 files changed, 12 insertions, 10 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index dfc2df5..91b5ad8 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -746,14 +746,13 @@ static int acpiphp_bus_add(struct acpiphp_func *func)
 		dbg("acpi_bus_trim return %x\n", ret_val);
 	}
 
-	ret_val = acpi_bus_add(func->handle, &device);
-	if (ret_val) {
-		dbg("error adding bus, %x\n",
-			-ret_val);
-		goto acpiphp_bus_add_out;
-	}
+	ret_val = acpi_bus_add(func->handle);
+	if (!ret_val)
+		ret_val = acpi_bus_get_device(func->handle, &device);
+
+	if (ret_val)
+		dbg("error adding bus, %x\n", -ret_val);
 
-acpiphp_bus_add_out:
 	return ret_val;
 }
 
@@ -1130,10 +1129,14 @@ static void handle_bridge_insertion(acpi_handle handle, u32 type)
 		return;
 	}
 
-	if (acpi_bus_add(handle, &device)) {
+	if (acpi_bus_add(handle)) {
 		err("cannot add bridge to acpi list\n");
 		return;
 	}
+	if (acpi_bus_get_device(handle, &device)) {
+		err("ACPI device object missing\n");
+		return;
+	}
 	if (!acpiphp_configure_bridge(handle))
 		add_bridge(handle);
 	else
diff --git a/drivers/pci/hotplug/sgi_hotplug.c b/drivers/pci/hotplug/sgi_hotplug.c
index 801b58d..f3c4192 100644
--- a/drivers/pci/hotplug/sgi_hotplug.c
+++ b/drivers/pci/hotplug/sgi_hotplug.c
@@ -412,7 +412,6 @@ static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 	if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 		unsigned long long adr;
 		struct acpi_device *pdevice;
-		struct acpi_device *device;
 		acpi_handle phandle;
 		acpi_handle chandle = NULL;
 		acpi_handle rethandle;
@@ -448,7 +447,7 @@ static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 			if (ACPI_SUCCESS(ret) &&
 			    (adr>>16) == (slot->device_num + 1)) {
 
-				ret = acpi_bus_add(chandle, &device);
+				ret = acpi_bus_add(chandle);
 				if (ACPI_FAILURE(ret)) {
 					printk(KERN_ERR "%s: acpi_bus_add "
 					       "failed (0x%x) for slot %d "