[PATCH 4.4 07/30] ACPI / video: skip evaluating _DOD when it does not exist

Greg Kroah-Hartman
2017-03-24T18:04:43Z

From: Alex Hung <alex.hung@canonical.com>

commit e34fbbac669de0b7fb7803929d0477f35f6e2833 upstream.

Some system supports hybrid graphics and its discrete VGA
does not have any connectors and therefore has no _DOD method.

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/acpi/acpi_video.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1211,6 +1211,9 @@ static int acpi_video_device_enumerate(s
union acpi_object *dod = NULL;
union acpi_object *obj;

+ if (!video->cap._DOD)
+ return AE_NOT_EXIST;
+
status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
if (!ACPI_SUCCESS(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));