static irqreturn_t r592_irq()

in host/r592.c [625:678]

• 38 lines of code
• 6 McCabe index (conditional complexity)

static irqreturn_t r592_irq(int irq, void *data)
{
	struct r592_device *dev = (struct r592_device *)data;
	irqreturn_t ret = IRQ_NONE;
	u32 reg;
	u16 irq_enable, irq_status;
	unsigned long flags;
	int error;

	spin_lock_irqsave(&dev->irq_lock, flags);

	reg = r592_read_reg(dev, R592_REG_MSC);
	irq_enable = reg >> 16;
	irq_status = reg & 0xFFFF;

	/* Ack the interrupts */
	reg &= ~irq_status;
	r592_write_reg(dev, R592_REG_MSC, reg);

	/* Get the IRQ status minus bits that aren't enabled */
	irq_status &= (irq_enable);

	/* Due to limitation of memstick core, we don't look at bits that
		indicate that card was removed/inserted and/or present */
	if (irq_status & (R592_REG_MSC_IRQ_INSERT | R592_REG_MSC_IRQ_REMOVE)) {

		bool card_was_added = irq_status & R592_REG_MSC_IRQ_INSERT;
		ret = IRQ_HANDLED;

		message("IRQ: card %s", card_was_added ? "added" : "removed");

		mod_timer(&dev->detect_timer,
			jiffies + msecs_to_jiffies(card_was_added ? 500 : 50));
	}

	if (irq_status &
		(R592_REG_MSC_FIFO_DMA_DONE | R592_REG_MSC_FIFO_DMA_ERR)) {
		ret = IRQ_HANDLED;

		if (irq_status & R592_REG_MSC_FIFO_DMA_ERR) {
			message("IRQ: DMA error");
			error = -EIO;
		} else {
			dbg_verbose("IRQ: dma done");
			error = 0;
		}

		r592_stop_dma(dev, error);
		complete(&dev->dma_done);
	}

	spin_unlock_irqrestore(&dev->irq_lock, flags);
	return ret;
}