static int tpci200_request_irq()

in carriers/tpci200.c [189:237]

• 36 lines of code
• 5 McCabe index (conditional complexity)

static int tpci200_request_irq(struct ipack_device *dev,
			       irqreturn_t (*handler)(void *), void *arg)
{
	int res = 0;
	struct slot_irq *slot_irq;
	struct tpci200_board *tpci200;

	tpci200 = check_slot(dev);
	if (tpci200 == NULL)
		return -EINVAL;

	if (mutex_lock_interruptible(&tpci200->mutex))
		return -ERESTARTSYS;

	if (tpci200->slots[dev->slot].irq != NULL) {
		dev_err(&dev->dev,
			"Slot [%d:%d] IRQ already registered !\n",
			dev->bus->bus_nr,
			dev->slot);
		res = -EINVAL;
		goto out_unlock;
	}

	slot_irq = kzalloc(sizeof(struct slot_irq), GFP_KERNEL);
	if (slot_irq == NULL) {
		dev_err(&dev->dev,
			"Slot [%d:%d] unable to allocate memory for IRQ !\n",
			dev->bus->bus_nr, dev->slot);
		res = -ENOMEM;
		goto out_unlock;
	}

	/*
	 * WARNING: Setup Interrupt Vector in the IndustryPack device
	 * before an IRQ request.
	 * Read the User Manual of your IndustryPack device to know
	 * where to write the vector in memory.
	 */
	slot_irq->handler = handler;
	slot_irq->arg = arg;
	slot_irq->holder = dev;

	rcu_assign_pointer(tpci200->slots[dev->slot].irq, slot_irq);
	tpci200_enable_irq(tpci200, dev->slot);

out_unlock:
	mutex_unlock(&tpci200->mutex);
	return res;
}