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>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index e3aed48..3d44c70 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1620,37 +1620,27 @@
return status;
}
-static int acpi_bus_scan(acpi_handle handle, struct acpi_device **child)
+static int acpi_bus_scan(acpi_handle handle)
{
void *device = NULL;
- acpi_status status;
- int ret = -ENODEV;
- status = acpi_bus_check_add(handle, 0, NULL, &device);
- if (ACPI_SUCCESS(status))
+ if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
acpi_bus_check_add, NULL, NULL, &device);
if (!device)
- goto out;
+ return -ENODEV;
- ret = 0;
- status = acpi_bus_device_attach(handle, 0, NULL, NULL);
- if (ACPI_SUCCESS(status))
+ if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
acpi_bus_device_attach, NULL, NULL, NULL);
- out:
- if (child)
- *child = device;
-
- return ret;
+ return 0;
}
/**
* acpi_bus_add - Add ACPI device node objects in a given namespace scope.
* @handle: Root of the namespace scope to scan.
- * @ret: Location to store a return struct acpi_device pointer.
*
* Scan a given ACPI tree (probably recently hot-plugged) and create and add
* found devices.
@@ -1659,21 +1649,12 @@
* there has been a real error. There just have been no suitable ACPI objects
* in the table trunk from which the kernel could create a device and add an
* appropriate driver.
- *
- * If 0 is returned, the memory location pointed to by @ret will be populated
- * with a pointer to a struct acpi_device created while scanning the namespace.
- * If @handle corresponds to a device node, that will be a pointer to the struct
- * acpi_device object corresponding to @handle. Otherwise, it will be a pointer
- * to a struct acpi_device corresponding to one of its descendants.
- *
- * If an error code is returned, NULL will be stored in the memory location
- * pointed to by @ret.
*/
-int acpi_bus_add(acpi_handle handle, struct acpi_device **ret)
+int acpi_bus_add(acpi_handle handle)
{
int err;
- err = acpi_bus_scan(handle, ret);
+ err = acpi_bus_scan(handle);
if (err)
return err;
@@ -1777,8 +1758,11 @@
/*
* Enumerate devices in the ACPI namespace.
*/
- result = acpi_bus_scan(ACPI_ROOT_OBJECT, &acpi_root);
+ result = acpi_bus_scan(ACPI_ROOT_OBJECT);
+ if (result)
+ return result;
+ result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
if (!result)
result = acpi_bus_scan_fixed();