pciehp_isr
static irqreturn_t pciehp_isr(int irq, void *dev_id);
retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist,
ret = pciehp_isr(irq, dev_id);
while (pciehp_isr(IRQ_NOTCONNECTED, ctrl) == IRQ_WAKE_THREAD ||