There is a fairly vague one sentence answer to this question, in the general rule case that does not involve an escalation of conflict by the person provoked with a deadly weapon that wasn't part of the original provocation, with little case law interpretation in the applicable Wisconsin statute. This sentence states:
The privilege lost by provocation may be regained if the actor in good
faith withdraws from the fight and gives adequate notice thereof to
his or her assailant.
Beyond that, in any remotely close case, it is up to the jury to decide what this sentence means.
The relevant Wisconsin statute states that:
Provocation affects the privilege of self-defense as follows:
(a) A person who engages in unlawful conduct of a type likely to
provoke others to attack him or her and thereby does provoke an attack
is not entitled to claim the privilege of self-defense against such
attack, except when the attack which ensues is of a type causing the
person engaging in the unlawful conduct to reasonably believe that he
or she is in imminent danger of death or great bodily harm. In such a
case, the person engaging in the unlawful conduct is privileged to act
in self-defense, but the person is not privileged to resort to the use
of force intended or likely to cause death to the person's assailant
unless the person reasonably believes he or she has exhausted every
other reasonable means to escape from or otherwise avoid death or
great bodily harm at the hands of his or her assailant.
(b) The privilege lost by provocation may be regained if the actor
in good faith withdraws from the fight and gives adequate notice
thereof to his or her assailant.
(c) A person who provokes an attack, whether by lawful or unlawful
conduct, with intent to use such an attack as an excuse to cause death
or great bodily harm to his or her assailant is not entitled to claim
the privilege of self-defense.
Wis. Stat. Ann. § 939.48(2).
There are two reported appellate case precedents in Wisconsin that have addressed this question and interpreted this statutory provision.
One from the Wisconsin Court of Appeals is State v. Cummings, 451 N.W.2d 463 (Wisc. App. 1989). It held that when a prisoner was charged with assault based on his biting officer who was one of several officers restraining him when he became agitated while in hospital for treatment was not entitled to self-defense instruction in prosecution for battery to correctional officer because the prisoner was engaging in unlawful conduct when he refused to obey officer's direct orders and physically resisted officers as they attempted to restrain him, and prisoner's own testimony was that officer's arm was on his throat for only a few seconds, which constituted brief and legitimate response to resistance that prisoner was putting forth. This primarily addresses part (a), however.
The other from the Wisconsin Supreme Court is Ruff v. State, 223 N.W.2d 446 (Wisc. 1974) which held that if a person attacked escalated fight beyond that which would be legally justifiable in view of nature of original provocation, aggressor would regain privilege of self-defense, because victim, by resorting to deadly force which was not a justifiable exercise of right of self-defense, would himself become aggressor. Thus, the right to regain right of self-defense was not available to defendant at moment when he pointed gun at intended victim and stated “This is a stickup,” since at that moment, the right of self-defense was limited to the person at whom defendant's gun was pointed, not on side of defendant commencing a stick-up. This primarily addresses part (c), however.
There is no binding case law interpreting part (b) in Wisconsin that is squarely on point.
Wisconsin's rule on this point codifies the common law rule, so Wisconsin cases prior to the enactment of this statutory rule, and out of state precedents interpreting that common law rule or codifications of it that are very similar to Wisconsin's statutory rule, would probably be considered persuasive by a court seeking to interpret and apply this statutory rule.
In the alternative, the judge might simply have a jury instruction that contains the language of part (b) and simply leave the jury to decide what this means based upon its plain language and the facts before them, where the facts of the case present a colorable withdrawal of provocation issue.