diff --git a/example/ck_tile/18_flatmm/run_flatmm_example.inc b/example/ck_tile/18_flatmm/run_flatmm_example.inc
index b583612cfb..8f39b07be5 100644
--- a/example/ck_tile/18_flatmm/run_flatmm_example.inc
+++ b/example/ck_tile/18_flatmm/run_flatmm_example.inc
@@ -18,7 +18,7 @@ constexpr const char* DataTypeToString()
     {
         return "bf8";
     }
-    else if  constexpr(std::is_same_v<T, ck_tile::bf16_t>)
+    else if constexpr(std::is_same_v<T, ck_tile::bf16_t>)
     {
         return "bf16";
     }
diff --git a/example/ck_tile/36_copy/test_copy.hpp b/example/ck_tile/36_copy/test_copy.hpp
index 3c1c9bb9ed..7285b4a29f 100644
--- a/example/ck_tile/36_copy/test_copy.hpp
+++ b/example/ck_tile/36_copy/test_copy.hpp
@@ -130,6 +130,7 @@ struct TileCopy
                              make_tuple(number<S::Block_M>{}, number<S::Block_N>{}),
                              {iM, 0},
                              MakeDRAMDistribution<Problem>());
+        // We don't have prefetch here, wait the data back immediately.
         constexpr auto async_copy_fence_cnt = 0;
 
         // Output tensor
diff --git a/include/ck_tile/core/arch/arch.hpp b/include/ck_tile/core/arch/arch.hpp
index 8c0b9d56d7..33572b38c5 100644
--- a/include/ck_tile/core/arch/arch.hpp
+++ b/include/ck_tile/core/arch/arch.hpp
@@ -116,8 +116,10 @@ CK_TILE_DEVICE void block_sync_load_raw(index_t cnt = 0)
 template <index_t vmcnt>
 CK_TILE_DEVICE void block_sync_lds_direct_load()
 {
+    // we maximum track 64 insts back
+    static_assert(vmcnt <= 63);
     // We don't sync the lds insts here.
-    constexpr auto s_waitcnt_imm = 3952 + ((vmcnt >> 4) << 14) + (vmcnt & 0xff);
+    constexpr auto s_waitcnt_imm = 3952 + (((vmcnt & 0xf0) << 10) | (vmcnt & 0xf));
     __builtin_amdgcn_s_waitcnt(s_waitcnt_imm);
     __builtin_amdgcn_s_barrier();
 }