drm/virtio: simplify cursor updates

No need to do the reservation dance,
we can just wait on the fence directly.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190829103301.3539-4-kraxel@redhat.com

drivers/gpu/drm/virtio/virtgpu_plane.c

@@ -201,7 +201,6 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 	struct virtio_gpu_framebuffer *vgfb;
 	struct virtio_gpu_object *bo = NULL;
 	uint32_t handle;
-	int ret = 0;
 
 	if (plane->state->crtc)
 		output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
@@ -225,15 +224,9 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 			 cpu_to_le32(plane->state->crtc_w),
 			 cpu_to_le32(plane->state->crtc_h),
 			 0, 0, vgfb->fence);
-		ret = virtio_gpu_object_reserve(bo, false);
-		if (!ret) {
-			dma_resv_add_excl_fence(bo->tbo.base.resv,
-							  &vgfb->fence->f);
-			dma_fence_put(&vgfb->fence->f);
-			vgfb->fence = NULL;
-			virtio_gpu_object_unreserve(bo);
-			virtio_gpu_object_wait(bo, false);
-		}
+		dma_fence_wait(&vgfb->fence->f, true);
+		dma_fence_put(&vgfb->fence->f);
+		vgfb->fence = NULL;
 	}
 
 	if (plane->state->fb != old_state->fb) {