diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2009-09-21 19:29:50 (GMT) |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-09-25 18:24:29 (GMT) |
| commit | 859ac9a4be0c753cece0e30a2e4a65fd2cdcaeee (patch) | |
| tree | 10962790433ee0865ab6506c69981e8248368e46 /drivers/acpi | |
| parent | adc08e2035f1859d4b129f42b2c2305ef090d226 (diff) | |
| download | linux-859ac9a4be0c753cece0e30a2e4a65fd2cdcaeee.tar.xz | |
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>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/scan.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 27d2dec..0b5aaf0 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -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; |