diff --git a/camera/camera2/ICameraDeviceCallbacks.cpp b/camera/camera2/ICameraDeviceCallbacks.cpp
index 4cc7b5d..f599879 100644
--- a/camera/camera2/ICameraDeviceCallbacks.cpp
+++ b/camera/camera2/ICameraDeviceCallbacks.cpp
@@ -37,6 +37,7 @@
     CAMERA_IDLE,
     CAPTURE_STARTED,
     RESULT_RECEIVED,
+    PREPARED
 };
 
 class BpCameraDeviceCallbacks: public BpInterface<ICameraDeviceCallbacks>
@@ -80,7 +81,6 @@
         data.writeNoException();
     }
 
-
     void onResultReceived(const CameraMetadata& metadata,
             const CaptureResultExtras& resultExtras) {
         ALOGV("onResultReceived");
@@ -93,6 +93,17 @@
         remote()->transact(RESULT_RECEIVED, data, &reply, IBinder::FLAG_ONEWAY);
         data.writeNoException();
     }
+
+    void onPrepared(int streamId)
+    {
+        ALOGV("onPrepared");
+        Parcel data, reply;
+        data.writeInterfaceToken(ICameraDeviceCallbacks::getInterfaceDescriptor());
+        data.writeInt32(streamId);
+        remote()->transact(PREPARED, data, &reply, IBinder::FLAG_ONEWAY);
+        data.writeNoException();
+    }
+
 };
 
 IMPLEMENT_META_INTERFACE(CameraDeviceCallbacks,
@@ -160,6 +171,15 @@
             data.readExceptionCode();
             return NO_ERROR;
         } break;
+        case PREPARED: {
+            ALOGV("onPrepared");
+            CHECK_INTERFACE(ICameraDeviceCallbacks, data, reply);
+            CaptureResultExtras result;
+            int streamId = data.readInt32();
+            onPrepared(streamId);
+            data.readExceptionCode();
+            return NO_ERROR;
+        } break;
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/camera/camera2/ICameraDeviceUser.cpp b/camera/camera2/ICameraDeviceUser.cpp
index 2ec08a9..9700258 100644
--- a/camera/camera2/ICameraDeviceUser.cpp
+++ b/camera/camera2/ICameraDeviceUser.cpp
@@ -47,7 +47,8 @@
     CREATE_DEFAULT_REQUEST,
     GET_CAMERA_INFO,
     WAIT_UNTIL_IDLE,
-    FLUSH
+    FLUSH,
+    PREPARE
 };
 
 namespace {
@@ -348,6 +349,20 @@
         return res;
     }
 
+    virtual status_t prepare(int streamId)
+    {
+        ALOGV("prepare");
+        Parcel data, reply;
+
+        data.writeInterfaceToken(ICameraDeviceUser::getInterfaceDescriptor());
+        data.writeInt32(streamId);
+
+        remote()->transact(PREPARE, data, &reply);
+
+        reply.readExceptionCode();
+        return reply.readInt32();
+    }
+
 private:
 
 
@@ -545,6 +560,14 @@
             reply->writeInt32(endConfigure());
             return NO_ERROR;
         } break;
+        case PREPARE: {
+            CHECK_INTERFACE(ICameraDeviceUser, data, reply);
+            int streamId = data.readInt32();
+            reply->writeNoException();
+            reply->writeInt32(prepare(streamId));
+            return NO_ERROR;
+        } break;
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }