When we scan all the acpi namespace node in acpi_scan_init()->acpi_bus_scan(), we evaluate '_STA' method for processor type node to determine whether the device is present. But processors can also be declared via ASL Device statement. ACPI 6.3 spec specifically says that the Processor statement is deprecated and a Device statement should be used for processors. In that case, acpi_object_type is ACPI_TYPE_DEVICE rather than ACPI_TYPE_PROCESSOR. Current code doesn't evaluate '_STA' for nodes with ACPI_TYPE_DEVICE, and the device status is set to 'present' as default. This patch get the device status from '_STA' method for processors declared via ASL Device statement if it does have a '_STA' method. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx> --- I am not sure if I should set 'type' as ACPI_BUS_TYPE_PROCESSOR rather than ACPI_BUS_TYPE_DEVICE for processors declared via ASL Device statement. --- drivers/acpi/scan.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 0e28270..cec43f6 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -16,6 +16,7 @@ #include <linux/dma-mapping.h> #include <linux/platform_data/x86/apple.h> +#include <acpi/processor.h> #include <asm/pgtable.h> #include "internal.h" @@ -1687,6 +1688,7 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type, { acpi_status status; acpi_object_type acpi_type; + struct acpi_device_info *info; status = acpi_get_type(handle, &acpi_type); if (ACPI_FAILURE(status)) @@ -1699,6 +1701,16 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type, return -ENODEV; *type = ACPI_BUS_TYPE_DEVICE; + + status = acpi_get_object_info(handle, &info); + if (ACPI_SUCCESS(status) && info->valid & ACPI_VALID_HID && + !strcmp(info->hardware_id.string, + ACPI_PROCESSOR_DEVICE_HID)) { + status = acpi_bus_get_status_handle(handle, sta); + if (ACPI_SUCCESS(status)) + break; + } + /* * acpi_add_single_object updates this once we've an acpi_device * so that acpi_bus_get_status' quirk handling can be used. -- 1.7.12.4