[PATCH v1 4/4] ACPI: scan: Make acpi_processor_add() check the device enabled bit

["Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>]

From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Modify acpi_processor_add() return an error if _STA returns the enabled
bit clear for the given processor device, so as to avoid using processors
that don't decode their resources, as per the ACPI specification. [1]

Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#sta-device-status # [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
 drivers/acpi/acpi_processor.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-pm/drivers/acpi/acpi_processor.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_processor.c
+++ linux-pm/drivers/acpi/acpi_processor.c
@@ -381,6 +381,9 @@ static int acpi_processor_add(struct acp
 	struct device *dev;
 	int result = 0;
 
+	if (!acpi_device_is_enabled(device))
+		return -ENODEV;
+
 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 	if (!pr)
 		return -ENOMEM;