diff --git a/modules/camera/3_4/v4l2_wrapper.cpp b/modules/camera/3_4/v4l2_wrapper.cpp
index bce3200..d331a77 100644
--- a/modules/camera/3_4/v4l2_wrapper.cpp
+++ b/modules/camera/3_4/v4l2_wrapper.cpp
@@ -231,12 +231,19 @@
                             int32_t* result) {
   HAL_LOG_ENTER();
 
+  // TODO(b/29334616): When async, this may need to check if the stream
+  // is on, and if so, lock it off while setting format. Need to look
+  // into if V4L2 supports adjusting controls while the stream is on.
+
   v4l2_control control{control_id, desired};
   if (IoctlLocked(VIDIOC_S_CTRL, &control) < 0) {
     HAL_LOGE("S_CTRL fails: %s", strerror(errno));
     return -ENODEV;
   }
-  *result = control.value;
+  // If the caller wants to know the result, pass it back.
+  if (result != nullptr) {
+    *result = control.value;
+  }
   return 0;
 }
 
diff --git a/modules/camera/3_4/v4l2_wrapper.h b/modules/camera/3_4/v4l2_wrapper.h
index d67b36e..113499a 100644
--- a/modules/camera/3_4/v4l2_wrapper.h
+++ b/modules/camera/3_4/v4l2_wrapper.h
@@ -45,7 +45,8 @@
   // Manage controls.
   int QueryControl(uint32_t control_id, v4l2_query_ext_ctrl* result);
   int GetControl(uint32_t control_id, int32_t* value);
-  int SetControl(uint32_t control_id, int32_t desired, int32_t* result);
+  int SetControl(uint32_t control_id, int32_t desired,
+                 int32_t* result = nullptr);
   // Manage format.
   int SetFormat(const default_camera_hal::Stream& stream,
                 uint32_t* result_max_buffers);