static int __init isapnp_init()

in isapnp/core.c [953:1045]

• 83 lines of code
• 18 McCabe index (conditional complexity)

static int __init isapnp_init(void)
{
	int cards;
	struct pnp_card *card;
	struct pnp_dev *dev;

	if (isapnp_disable) {
		printk(KERN_INFO "isapnp: ISA Plug & Play support disabled\n");
		return 0;
	}
#ifdef CONFIG_PPC
	if (check_legacy_ioport(_PIDXR) || check_legacy_ioport(_PNPWRP))
		return -EINVAL;
#endif
#ifdef ISAPNP_REGION_OK
	if (!request_region(_PIDXR, 1, "isapnp index")) {
		printk(KERN_ERR "isapnp: Index Register 0x%x already used\n",
		       _PIDXR);
		return -EBUSY;
	}
#endif
	if (!request_region(_PNPWRP, 1, "isapnp write")) {
		printk(KERN_ERR
		       "isapnp: Write Data Register 0x%x already used\n",
		       _PNPWRP);
#ifdef ISAPNP_REGION_OK
		release_region(_PIDXR, 1);
#endif
		return -EBUSY;
	}

	if (pnp_register_protocol(&isapnp_protocol) < 0)
		return -EBUSY;

	/*
	 *      Print a message. The existing ISAPnP code is hanging machines
	 *      so let the user know where.
	 */

	printk(KERN_INFO "isapnp: Scanning for PnP cards...\n");
	if (isapnp_rdp >= 0x203 && isapnp_rdp <= 0x3ff) {
		isapnp_rdp |= 3;
		if (!request_region(isapnp_rdp, 1, "isapnp read")) {
			printk(KERN_ERR
			       "isapnp: Read Data Register 0x%x already used\n",
			       isapnp_rdp);
#ifdef ISAPNP_REGION_OK
			release_region(_PIDXR, 1);
#endif
			release_region(_PNPWRP, 1);
			return -EBUSY;
		}
		isapnp_set_rdp();
	}
	if (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff) {
		cards = isapnp_isolate();
		if (cards < 0 || (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff)) {
#ifdef ISAPNP_REGION_OK
			release_region(_PIDXR, 1);
#endif
			release_region(_PNPWRP, 1);
			printk(KERN_INFO
			       "isapnp: No Plug & Play device found\n");
			return 0;
		}
		request_region(isapnp_rdp, 1, "isapnp read");
	}
	isapnp_build_device_list();
	cards = 0;

	protocol_for_each_card(&isapnp_protocol, card) {
		cards++;
		if (isapnp_verbose) {
			dev_info(&card->dev, "card '%s'\n",
			       card->name[0] ? card->name : "unknown");
			if (isapnp_verbose < 2)
				continue;
			card_for_each_dev(card, dev) {
				dev_info(&card->dev, "device '%s'\n",
				       dev->name[0] ? dev->name : "unknown");
			}
		}
	}
	if (cards)
		printk(KERN_INFO
		       "isapnp: %i Plug & Play card%s detected total\n", cards,
		       cards > 1 ? "s" : "");
	else
		printk(KERN_INFO "isapnp: No Plug & Play card found\n");

	isapnp_proc_init();
	return 0;
}