 if (irq >= NR_IRQS) return; 
void enable_irq(unsigned int irq){	irq_desc_t *desc = irq_desc + irq;	unsigned long flags;	spin_lock_irqsave(&desc->lock, flags);	switch (desc->depth) {	case 0:		WARN_ON(1);		break;	case 1: {		unsigned int status = desc->status & ~IRQ_DISABLED;		desc->status = status;		if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {			desc->status = status | IRQ_REPLAY;			hw_resend_irq(desc->handler,irq);		}		desc->handler->enable(irq);		/* fall-through */	}	default:		desc->depth--;	}	spin_unlock_irqrestore(&desc->lock, flags);}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/c2b5a251b9feca727661f1a3278cafb1de4c80f3/manage.c/buggy/kernel/irq/manage.c