From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
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@xxxxxxxxx>
---
drivers/acpi/scan.c | 60 +++++++++-------------------------------------------
1 file changed, 11 insertions(+), 49 deletions(-)
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1425,17 +1425,20 @@ static void acpi_device_set_id(struct ac
}
}
-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;
}
void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
@@ -1646,51 +1649,10 @@ EXPORT_SYMBOL(acpi_bus_add);
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;
+ 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);
--
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