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: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 8456e8cbf9fd..bc7a69516dce 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -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