[PATCH v3 11/17] ACPI: convert acpi_bus_scan() to operate on an acpi_handle

Bjorn Helgaas
2009-09-21T19:29:37Z

This patch changes acpi_bus_scan() to take an acpi_handle rather than an
acpi_device pointer. I plan to use acpi_bus_scan() in the hotplug path,
and I'd rather not assume that notifications only go to nodes that already
have acpi_devices.

This will also help remove the special case for adding the root node. We
currently add the root by hand before acpi_bus_scan(), but using a handle
here means we can start the acpi_bus_scan() directly with the root even
though it doesn't have an acpi_device yet.

Note that acpi_bus_scan() currently adds and/or starts the *children* of
its device argument. It doesn't do anything with the device itself.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---
drivers/acpi/scan.c | 34 +++++++++++++++++-----------------
1 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f205b36..4fe7359 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1387,7 +1387,7 @@ end:
return result;
}

-static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
+static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops)
{
acpi_status status = AE_OK;
struct acpi_device *parent = NULL;
@@ -1396,13 +1396,16 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
acpi_handle chandle = NULL;
acpi_object_type type = 0;
u32 level = 1;
+ int ret;

-
- if (!start)
- return -EINVAL;
-
- parent = start;
- phandle = start->handle;
+ /*
+ * We must have an acpi_device for the starting node already, and
+ * we scan its children.
+ */
+ phandle = handle;
+ ret = acpi_bus_get_device(phandle, &parent);
+ if (ret)
+ return ret;

/*
* Parse through the ACPI namespace, identify all 'devices', and
@@ -1516,7 +1519,7 @@ acpi_bus_add(struct acpi_device **child,

result = acpi_add_single_object(child, handle, type, &ops);
if (!result)
- result = acpi_bus_scan(*child, &ops);
+ result = acpi_bus_scan((*child)->handle, &ops);

return result;
}
@@ -1527,16 +1530,13 @@ int acpi_bus_start(struct acpi_device *device)
int result;
struct acpi_bus_ops ops;

-
- if (!device)
- return -EINVAL;
+ memset(&ops, 0, sizeof(ops));
+ ops.acpi_op_start = 1;

result = acpi_start_single_object(device);
- if (!result) {
- memset(&ops, 0, sizeof(ops));
- ops.acpi_op_start = 1;
- result = acpi_bus_scan(device, &ops);
- }
+ if (!result)
+ result = acpi_bus_scan(device->handle, &ops);
+
return result;
}
EXPORT_SYMBOL(acpi_bus_start);
@@ -1653,7 +1653,7 @@ int __init acpi_scan_init(void)
result = acpi_bus_scan_fixed();

if (!result)
- result = acpi_bus_scan(acpi_root, &ops);
+ result = acpi_bus_scan(acpi_root->handle, &ops);

if (result)
acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);