diff --git a/include/dm/device.h b/include/dm/device.h
index 160cd58..56862d3 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -139,6 +139,10 @@
  * @per_child_auto_alloc_size: Each device can hold private data owned by
  * its parent. If required this will be automatically allocated if this
  * value is non-zero.
+ * TODO(sjg@chromium.org): I'm considering dropping this, and just having
+ * device_probe_child() pass it in. So far the use case for allocating it
+ * is SPI, but I found that unsatisfactory. Since it is here I will leave it
+ * until things are clearer.
  * @ops: Driver-specific operations. This is typically a list of function
  * pointers defined by the driver, to implement driver functions required by
  * the uclass.