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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: benh@kernel.crashing.org
Subject: Re: [RFC 1/3] hvc_console: rework setup to replace irq functions with callbacks
Date: Mon, 13 Oct 2008 10:47:12 +0200
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Am Montag, 13. Oktober 2008 schrieb Benjamin Herrenschmidt:
> 
> >  	if (--hp->count == 0) {
> > -		if (hp->ops->notifier_del)
> > -			hp->ops->notifier_del(hp, hp->data);
> > -
> >  		/* We are done with the tty pointer now. */
> >  		hp->tty = NULL;
> >  		spin_unlock_irqrestore(&hp->lock, flags);
> >  
> > +		if (hp->ops->notifier_del)
> > +			hp->ops->notifier_del(hp, hp->data);
> > +
> 
> I will try. Of course the risk here is that the interrupt happens
> after we set hp->tty to NULL, so we probably need to check within the
> interrupt handler for a NULL tty. I haven't checked if that's the case
> (I'm not in front of the code right now).

Even the old code (without my patch) was setting hp->tty to NULL before doing 
the irq_free, so that should be ok.

Christian