On Fri, 31 Jul 2009, Bjorn Helgaas wrote:
> 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@xxxxxx>
> ---
> drivers/acpi/scan.c | 18 +++++++++++-------
> include/acpi/acpi_bus.h | 1 -
> 2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index b97b2ad..c0736f6 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -950,10 +950,12 @@ 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 (!device->parent) {
it is just a style thing, but i probably would
use a macro for this, such as ACPI_IS_ROOT(device)
to make the code read easier to the un-initiated.
thanks,
-Len Brown, Intel Open Source Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
