ACPI: Make acpi_bus_add() and acpi_bus_start() visibly different

The current ACPI namespace scanning code suggests that acpi_bus_add()
and acpi_bus_start() share some code.  In fact, however, they are
completely different code paths (except for the initial checks), so
refactor the code to make that distinction visibly clear.

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 a7e81ac..f3bcaf6 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1623,10 +1623,9 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
        return AE_OK;
 }
 
-static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl,
-                                       void *context, void **not_used)
+static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
+                                         void *not_used, void **ret_not_used)
 {
-       struct acpi_bus_ops *ops = context;
        acpi_status status = AE_OK;
        struct acpi_device *device;
        unsigned long long sta_not_used;
@@ -1642,16 +1641,11 @@ static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl,
        if (acpi_bus_get_device(handle, &device))
                return AE_CTRL_DEPTH;
 
-       if (ops->acpi_op_add) {
-               if (!acpi_match_device_ids(device, acpi_platform_device_ids)) {
-                       /* This is a known good platform device. */
-                       acpi_create_platform_device(device);
-               } else if (device_attach(&device->dev)) {
-                       status = AE_CTRL_DEPTH;
-               }
-       } else if (ops->acpi_op_start) {
-               if (ACPI_FAILURE(acpi_start_single_object(device)))
-                       status = AE_CTRL_DEPTH;
+       if (!acpi_match_device_ids(device, acpi_platform_device_ids)) {
+               /* This is a known good platform device. */
+               acpi_create_platform_device(device);
+       } else if (device_attach(&device->dev)) {
+               status = AE_CTRL_DEPTH;
        }
        return status;
 }
@@ -1672,10 +1666,10 @@ static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops,
                goto out;
 
        ret = 0;
-       status = acpi_bus_probe_start(handle, 0, ops, NULL);
+       status = acpi_bus_device_attach(handle, 0, NULL, NULL);
        if (ACPI_SUCCESS(status))
                acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
-                                   acpi_bus_probe_start, NULL, ops, NULL);
+                                   acpi_bus_device_attach, NULL, NULL, NULL);
 
  out:
        if (child)
@@ -1700,31 +1694,44 @@ int
 acpi_bus_add(struct acpi_device **child,
             struct acpi_device *parent, acpi_handle handle, int type)
 {
-       struct acpi_bus_ops ops;
-
-       memset(&ops, 0, sizeof(ops));
-       ops.acpi_op_add = 1;
+       struct acpi_bus_ops ops = { .acpi_op_add = 1, };
 
        return acpi_bus_scan(handle, &ops, child);
 }
 EXPORT_SYMBOL(acpi_bus_add);
 
-int acpi_bus_start(struct acpi_device *device)
+static acpi_status acpi_bus_start_device(acpi_handle handle, u32 lvl,
+                                        void *not_used, void **ret_not_used)
 {
-       struct acpi_bus_ops ops;
-       int result;
+       struct acpi_device *device;
+       unsigned long long sta_not_used;
+       int type_not_used;
+
+       /*
+        * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
+        * namespace walks prematurely.
+        */
+       if (acpi_bus_type_and_status(handle, &type_not_used, &sta_not_used))
+               return AE_OK;
+
+       if (acpi_bus_get_device(handle, &device))
+               return AE_CTRL_DEPTH;
+
+       return acpi_start_single_object(device);
+}
 
+int acpi_bus_start(struct acpi_device *device)
+{
        if (!device)
                return -EINVAL;
 
-       memset(&ops, 0, sizeof(ops));
-       ops.acpi_op_start = 1;
-
-       result = acpi_bus_scan(device->handle, &ops, NULL);
+       if (ACPI_SUCCESS(acpi_start_single_object(device)))
+               acpi_walk_namespace(ACPI_TYPE_ANY, device->handle,
+                                   ACPI_UINT32_MAX, acpi_bus_start_device,
+                                   NULL, NULL, NULL);
 
        acpi_update_all_gpes();
-
-       return result;
+       return 0;
 }
 EXPORT_SYMBOL(acpi_bus_start);