diff --git a/services/camera/libcameraservice/api1/Camera2Client.cpp b/services/camera/libcameraservice/api1/Camera2Client.cpp
index fe2f299..48ec730 100644
--- a/services/camera/libcameraservice/api1/Camera2Client.cpp
+++ b/services/camera/libcameraservice/api1/Camera2Client.cpp
@@ -1217,6 +1217,8 @@
     {
         SharedParameters::Lock l(mParameters);
         if (l.mParameters.state < Parameters::PREVIEW) {
+            ALOGE("%s: Camera %d: Call autoFocus when preview is inactive (state = %d).",
+                    __FUNCTION__, mCameraId, l.mParameters.state);
             return INVALID_OPERATION;
         }