wacom: allow for "no specific requested opcode" where we just return the data

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

tuhi/wacom.py

@@ -503,9 +503,9 @@ class WacomProtocolLowLevelComm(GObject.Object):
 
         # logger.debug(f'received {data.opcode:02x} / {data.length:02x} / {b2hex(bytes(data))}')
 
+        if expected_opcode is not None:
             if not isinstance(expected_opcode, list):
                 expected_opcode = [expected_opcode]
-
             if data.opcode not in expected_opcode:
                 raise WacomException(f'unexpected opcode: {data.opcode:02x}')