ACPI / scan: Change the implementation of acpi_bus_trim()
The current acpi_bus_trim() implementation is not really
straightforward and may be simplified significantly by using
acpi_walk_namespace() with acpi_bus_remove() as a post-order
callback.
Observe that acpi_bus_remove(), as called by acpi_bus_trim(), cannot
actually fail, because its first argument is guaranteed not to be
NULL thanks to the acpi_bus_get_device() check in acpi_bus_trim(),
so simply move the acpi_bus_get_device() check to acpi_bus_remove()
and use acpi_walk_namespace() to execute it for every device under
start->handle as a post-order callback. The, run it directly for
start->handle itself.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index d14ce44..1ee62bd 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1374,17 +1374,20 @@
return -ENODEV;
}
-static int acpi_bus_remove(struct acpi_device *dev)
+static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
+ void *not_used, void **ret_not_used)
{
- if (!dev)
- return -EINVAL;
+ struct acpi_device *dev = NULL;
+
+ if (acpi_bus_get_device(handle, &dev))
+ return AE_OK;
dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
device_release_driver(&dev->dev);
acpi_device_unregister(dev);
- return 0;
+ return AE_OK;
}
static int acpi_add_single_object(struct acpi_device **child,
@@ -1641,51 +1644,14 @@
int acpi_bus_trim(struct acpi_device *start)
{
- acpi_status status;
- struct acpi_device *parent, *child;
- acpi_handle phandle, chandle;
- acpi_object_type type;
- u32 level = 1;
- int err = 0;
-
- parent = start;
- phandle = start->handle;
- child = chandle = NULL;
-
- while ((level > 0) && parent && (!err)) {
- status = acpi_get_next_object(ACPI_TYPE_ANY, phandle,
- chandle, &chandle);
-
- /*
- * If this scope is exhausted then move our way back up.
- */
- if (ACPI_FAILURE(status)) {
- level--;
- chandle = phandle;
- acpi_get_parent(phandle, &phandle);
- child = parent;
- parent = parent->parent;
- err = acpi_bus_remove(child);
- continue;
- }
-
- status = acpi_get_type(chandle, &type);
- if (ACPI_FAILURE(status)) {
- continue;
- }
- /*
- * If there is a device corresponding to chandle then
- * parse it (depth-first).
- */
- if (acpi_bus_get_device(chandle, &child) == 0) {
- level++;
- phandle = chandle;
- chandle = NULL;
- parent = child;
- }
- continue;
- }
- return err;
+ /*
+ * Execute acpi_bus_remove() as a post-order callback to remove device
+ * nodes in the given namespace scope.
+ */
+ acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
+ acpi_bus_remove, NULL, NULL);
+ acpi_bus_remove(start->handle, 0, NULL, NULL);
+ return 0;
}
EXPORT_SYMBOL_GPL(acpi_bus_trim);