drm/radeon/kms: Skip ACPI call to ATIF when possible

I am under the impression that it only makes sense to call the ATIF
method if the graphics device has an ACPI handle attached. So we could
skip the call altogether if there is no such handle.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_acpi.c b/drivers/gpu/drm/radeon/radeon_acpi.c
index c039e5a..3516a60 100644
--- a/drivers/gpu/drm/radeon/radeon_acpi.c
+++ b/drivers/gpu/drm/radeon/radeon_acpi.c
@@ -51,13 +51,13 @@
 	acpi_handle handle;
 	int ret;
 
-	/* No need to proceed if we're sure that ATIF is not supported */
-	if (!ASIC_IS_AVIVO(rdev) || !rdev->bios)
-		return 0;
-
 	/* Get the device handle */
 	handle = DEVICE_ACPI_HANDLE(&rdev->pdev->dev);
 
+	/* No need to proceed if we're sure that ATIF is not supported */
+	if (!ASIC_IS_AVIVO(rdev) || !rdev->bios || !handle)
+		return 0;
+
 	/* Call the ATIF method */
 	ret = radeon_atif_call(handle);
 	if (ret)