ACPI: Always check if _PRW is present before trying to evaluate it

Before evaluating _PRW for devices that are reported as inactive or
not present by their _STA control methods we should check if those
methods are actually present (otherwise the evaulation of _PRW will
obviously fail and a scary message will be printed unnecessarily).

Reported-by: Andreas Mohr <andi@lisas.de>
Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 64d4da0d6d52..b5e4dedb497d 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1388,7 +1388,6 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
         struct acpi_bus_ops *ops = context;
         int type;
         unsigned long long sta;
-        struct acpi_device_wakeup wakeup;
         struct acpi_device *device;
         acpi_status status;
         int result;
@@ -1399,7 +1398,13 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
 
         if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
             !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
-                acpi_bus_extract_wakeup_device_power_package(handle, &wakeup);
+                struct acpi_device_wakeup wakeup;
+                acpi_handle temp;
+
+                status = acpi_get_handle(handle, "_PRW", &temp);
+                if (ACPI_SUCCESS(status))
+                        acpi_bus_extract_wakeup_device_power_package(handle,
+                                                                     &wakeup);
                 return AE_CTRL_DEPTH;
         }