diff --git a/src/operators/kernel/central-arm-func/pool_arm_func.h b/src/operators/kernel/central-arm-func/pool_arm_func.h
index 1c22a2646ea4efd91e6c73333c21e0d0c56fcb17..f1065d4571ab512913412f7fb05b059ebc62ec40 100644
--- a/src/operators/kernel/central-arm-func/pool_arm_func.h
+++ b/src/operators/kernel/central-arm-func/pool_arm_func.h
@@ -83,6 +83,7 @@ void PoolCompute(const PoolParam<CPU> &param) {
 #if __aarch64__
     PoolBasic(pooling_type, ksize, strides, paddings, in_x, out);
 #else
+    /// todo: fix bug in Pool2x2
     if (pooling_type == "max") {
       math::Pool2x2Maxs2p0(strides, paddings, in_x, out);
     } else if (pooling_type == "avg") {