[PATCH rev.2 3/6] ACPI: Make acpi_bus_add() and acpi_bus_start() visibly different

From: Rafael J. Wysocki
Date: Thu Dec 13 2012 - 17:19:31 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

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@xxxxxxxxx>
---
drivers/acpi/scan.c | 68 +++++++++++++++++++++++++++++-----------------------
1 file changed, 38 insertions(+), 30 deletions(-)

Index: linux/drivers/acpi/scan.c
===================================================================
--- linux.orig/drivers/acpi/scan.c
+++ linux/drivers/acpi/scan.c
@@ -1622,10 +1622,9 @@ static acpi_status acpi_bus_check_add(ac
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;
@@ -1641,18 +1640,13 @@ static acpi_status acpi_bus_probe_start(
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 {
- int ret = device_attach(&device->dev);
- acpi_hot_add_bind(device);
- if (ret)
- status = AE_CTRL_DEPTH;
- }
- } else if (ops->acpi_op_start) {
- if (ACPI_FAILURE(acpi_start_single_object(device)))
+ if (!acpi_match_device_ids(device, acpi_platform_device_ids)) {
+ /* This is a known good platform device. */
+ acpi_create_platform_device(device);
+ } else {
+ int ret = device_attach(&device->dev);
+ acpi_hot_add_bind(device);
+ if (ret)
status = AE_CTRL_DEPTH;
}
return status;
@@ -1674,10 +1668,10 @@ static int acpi_bus_scan(acpi_handle han
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)
@@ -1702,31 +1696,45 @@ 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;
+ acpi_status status;
+
+ /*
+ * 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);


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