MPC8272: Edge triggered IRQ

[Dmytro Bablinyuk <dmytro.bablinyuk@rftechnology.com.au>]

I have pretty simple code that I did a long time ago

irqreturn_t irq_handler(int irq, void *dev_id, struct pt_regs *regs)
{
  ..
 return IRQ_HANDLED;
}


request_irq(irq,
            &irq_handler,
            SA_INTERRUPT,
            "irq handler",
             NULL);

That code runs on MPC8272 and 2.6.18 kernel.
It triggers IRQ on low level (I thought it was falling edge by default).
So, as long as I have input low level I have hundreds of calls. Pretty
much it keeps calling IRQ handling routine.
How do I make it to trigger on falling edge?

Thank you,

Dmytro