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>

drivers/gpu/drm/radeon/radeon_acpi.c

@@ -51,13 +51,13 @@ int radeon_acpi_init(struct radeon_device *rdev)
 	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)