ACPI button: don't try to use a non-existent lid device

If a call comes in to check the lid state but there's no lid device
present, we should return -ENODEV.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 9335b87c5174..0c9c6a9a002c 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -251,6 +251,9 @@ int acpi_lid_open(void)
         acpi_status status;
         unsigned long long state;
 
+        if (!lid_device)
+                return -ENODEV;
+
         status = acpi_evaluate_integer(lid_device->handle, "_LID", NULL,
                                        &state);
         if (ACPI_FAILURE(status))