static int pnp_assign_dma()

in manager.c [191:233]

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

static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
{
	struct resource *res, local_res;
	int i;

	/* DMA priority: this table is good for i386 */
	static unsigned short xtab[8] = {
		1, 3, 5, 6, 7, 0, 2, 4
	};

	res = pnp_find_resource(dev, rule->flags, IORESOURCE_DMA, idx);
	if (res) {
		pnp_dbg(&dev->dev, "  dma %d already set to %d flags %#lx\n",
			idx, (int) res->start, res->flags);
		return 0;
	}

	res = &local_res;
	res->flags = rule->flags | IORESOURCE_AUTO;
	res->start = -1;
	res->end = -1;

	if (!rule->map) {
		res->flags |= IORESOURCE_DISABLED;
		pnp_dbg(&dev->dev, "  dma %d disabled\n", idx);
		goto __add;
	}

	for (i = 0; i < 8; i++) {
		if (rule->map & (1 << xtab[i])) {
			res->start = res->end = xtab[i];
			if (pnp_check_dma(dev, res))
				goto __add;
		}
	}

	pnp_dbg(&dev->dev, "  couldn't assign dma %d\n", idx);
	return -EBUSY;

__add:
	pnp_add_dma_resource(dev, res->start, res->flags);
	return 0;
}