Commit 859ac9a4 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Len Brown
Browse files

ACPI: identify device tree root by null parent pointer, not ACPI_BUS_TYPE 



We can identify the root of the ACPI device tree by the fact that it
has no parent.  This is simpler than passing around ACPI_BUS_TYPE_SYSTEM
and will help remove special treatment of the device tree root.

Currently, we add the root by hand with ACPI_BUS_TYPE_SYSTEM.  If we
traverse the tree treating the root as just another device and use
acpi_get_type(), the root shows up as ACPI_TYPE_DEVICE.

Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent adc08e20

drivers/acpi/scan.c

+13 −7
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ extern struct acpi_device *acpi_root; 
#define ACPI_BUS_HID			"LNXSYBUS"

#define ACPI_BUS_DEVICE_NAME		"System Bus"



#define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)



static LIST_HEAD(acpi_device_list);

static LIST_HEAD(acpi_bus_id_list);

DEFINE_MUTEX(acpi_device_lock);
@@ -955,10 +957,12 @@ static void acpi_device_get_busid(struct acpi_device *device) 
	 * The device's Bus ID is simply the object name.

	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?

	 */

	switch (device->device_type) {

	case ACPI_BUS_TYPE_SYSTEM:

	if (ACPI_IS_ROOT_DEVICE(device)) {

		strcpy(device->pnp.bus_id, "ACPI");

		break;

		return;

	}



	switch (device->device_type) {

	case ACPI_BUS_TYPE_POWER_BUTTON:

		strcpy(device->pnp.bus_id, "PWRF");

		break;
@@ -1093,6 +1097,11 @@ static void acpi_device_set_id(struct acpi_device *device) 


	switch (device->device_type) {

	case ACPI_BUS_TYPE_DEVICE:

		if (ACPI_IS_ROOT_DEVICE(device)) {

			hid = ACPI_SYSTEM_HID;

			break;

		}



		status = acpi_get_object_info(device->handle, &info);

		if (ACPI_FAILURE(status)) {

			printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
@@ -1129,9 +1138,6 @@ static void acpi_device_set_id(struct acpi_device *device) 
	case ACPI_BUS_TYPE_PROCESSOR:

		hid = ACPI_PROCESSOR_OBJECT_HID;

		break;

	case ACPI_BUS_TYPE_SYSTEM:

		hid = ACPI_SYSTEM_HID;

		break;

	case ACPI_BUS_TYPE_THERMAL:

		hid = ACPI_THERMAL_HID;

		break;
@@ -1643,7 +1649,7 @@ int __init acpi_scan_init(void) 
	 * Create the root device in the bus's device tree

	 */

	result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,

					ACPI_BUS_TYPE_SYSTEM, &ops);

					ACPI_BUS_TYPE_DEVICE, &ops);

	if (result)

		goto Done;

include/acpi/acpi_bus.h

+0 −1
Original line number Diff line number Diff line
@@ -70,7 +70,6 @@ enum acpi_bus_device_type { 
	ACPI_BUS_TYPE_POWER,

	ACPI_BUS_TYPE_PROCESSOR,

	ACPI_BUS_TYPE_THERMAL,

	ACPI_BUS_TYPE_SYSTEM,

	ACPI_BUS_TYPE_POWER_BUTTON,

	ACPI_BUS_TYPE_SLEEP_BUTTON,

	ACPI_BUS_DEVICE_TYPE_COUNT

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