[linux-3.16-rc5/drivers/xen/events/events_base.c:249]: (style) Checking if unsigned variable 'irq' is less than zero.

    if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
        return 0;

Suggest new code

    if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq)))
        return 0;