diff --git a/3rdparty/HalideIR b/3rdparty/HalideIR
index 55ba1778fd264..e4a4c02764d37 160000
--- a/3rdparty/HalideIR
+++ b/3rdparty/HalideIR
@@ -1 +1 @@
-Subproject commit 55ba1778fd264c7507953552d8e51212ed11f748
+Subproject commit e4a4c02764d37c9c3db0d64c4996651a3ef9513c
diff --git a/3rdparty/dlpack b/3rdparty/dlpack
index 5c792cef3aee5..bee4d1dd8dc1e 160000
--- a/3rdparty/dlpack
+++ b/3rdparty/dlpack
@@ -1 +1 @@
-Subproject commit 5c792cef3aee54ad8b7000111c9dc1797f327b59
+Subproject commit bee4d1dd8dc1ee4a1fd8fa6a96476c2f8b7492a3
diff --git a/3rdparty/dmlc-core b/3rdparty/dmlc-core
index 3ffea8694adf9..4d49691f1a9d9 160000
--- a/3rdparty/dmlc-core
+++ b/3rdparty/dmlc-core
@@ -1 +1 @@
-Subproject commit 3ffea8694adf9c0363f9abbf162dc0e4a45b22c5
+Subproject commit 4d49691f1a9d944c3b0aa5e63f1db3cad1f941f8
diff --git a/python/tvm/_ffi/ndarray.py b/python/tvm/_ffi/ndarray.py
index 3deb888bd10c2..75089345c6fe6 100644
--- a/python/tvm/_ffi/ndarray.py
+++ b/python/tvm/_ffi/ndarray.py
@@ -284,7 +284,7 @@ def asnumpy(self):
         return np_arr
 
     def copybytesto(self, target):
-        assert(target.flags['C_CONTIGUOUS'])
+        assert target.flags['C_CONTIGUOUS']
         data = target.ctypes.data_as(ctypes.c_void_p)
         nbytes = ctypes.c_size_t(target.size * target.dtype.itemsize)
         _LIB.TVMArrayCopyToBytes(self.handle, data, nbytes)
diff --git a/python/tvm/custom_datatypes.py b/python/tvm/custom_datatypes.py
index 966234c9df551..7f4fc84e81e91 100644
--- a/python/tvm/custom_datatypes.py
+++ b/python/tvm/custom_datatypes.py
@@ -53,7 +53,7 @@ def register_op(lower_func, op_name, target, type_name, src_type_name=None):
         the argument to the Cast. If op_name is not "Cast", this is unused.
     """
 
-    if op_name is "Cast":
+    if op_name == "Cast":
         assert src_type_name is not None
         lower_func_name = "tvm.custom_datatypes.lower." + target + "." \
                           + op_name + "." + type_name + "." + src_type_name
@@ -81,11 +81,10 @@ def lower(op):
             dtype = "uint" + str(t.bits)
             if t.lanes > 1:
                 dtype += "x" + str(t.lanes)
-        if type(op) is _Cast:
+        if isinstance(op, _Cast):
             return _make.Call(dtype, extern_func_name, convert([op.value]),
                               _Call.Extern, None, 0)
-        else:
-            return _make.Call(dtype, extern_func_name, convert([op.a, op.b]),
-                              _Call.Extern, None, 0)
+        return _make.Call(dtype, extern_func_name, convert([op.a, op.b]),
+                          _Call.Extern, None, 0)
 
     return lower