In addition to what constitutes a permanent kundalini awakening- some people think it can only happen through the transformation of shaktipat. Some believe its karma after several lifetimes it just happens spontaneously. Some believe its this explosion of fire like energy up the spine. It can't be all of these! So what constitutes a real permanent kundalini awakening? I truly doubt anyone really knows the truth.
Kundalini can awaken due to either of those reasons. And it can be experienced as an explosion of fire or energy (prana) up the spine or the centre of the body.
Kundalini can also awaken because of an effective regular yoga practice, which is actually the most effective and the safest way to awaken kundalini.