drm/radeon/kms: always use writeback/events for fences on NI

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index e353430..26091d6 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -228,6 +228,11 @@
 				rdev->wb.use_event = true;
 		}
 	}
+	/* always use writeback/events on NI */
+	if (ASIC_IS_DCE5(rdev)) {
+		rdev->wb.enabled = true;
+		rdev->wb.use_event = true;
+	}
 
 	dev_info(rdev->dev, "WB %sabled\n", rdev->wb.enabled ? "en" : "dis");