Function device_attach

freebsd/kern/subr_bus.c:2933–2978

* @brief Attach a device driver to a device * * This function is a wrapper around the DEVICE_ATTACH() driver * method. In addition to calling DEVICE_ATTACH(), it initialises the * device's sysctl tree, optionally prints a description of the device * and queues a notification event for user-based device management * services. * * Normally this function is only called internally from * devi

 * @retval non-zero	some other unix error code
 */
int
device_attach(device_t dev)
{
	uint64_t attachtime;
	uint16_t attachentropy;
	int error;

	if (resource_disabled(dev->driver->name, dev->unit)) {
		device_disable(dev);
		if (bootverbose)
			 device_printf(dev, "disabled via hints entry\n");
		return (ENXIO);
	}

	device_sysctl_init(dev);
	if (!device_is_quiet(dev))
		device_print_child(dev->parent, dev);
	attachtime = get_cyclecount();
	dev->state = DS_ATTACHING;
	if ((error = DEVICE_ATTACH(dev)) != 0) {
		printf("device_attach: %s%d attach returned %d\n",
		    dev->driver->name, dev->unit, error);
		if (!(dev->flags & DF_FIXEDCLASS))
			devclass_delete_device(dev->devclass, dev);
		(void)device_set_driver(dev, NULL);
		device_sysctl_fini(dev);
		KASSERT(dev->busy == 0, ("attach failed but busy"));
		dev->state = DS_NOTPRESENT;
		return (error);
	}
	dev->flags |= DF_ATTACHED_ONCE;
	/* We only need the low bits of this time, but ranges from tens to thousands
	 * have been seen, so keep 2 bytes' worth.
	 */
	attachentropy = (uint16_t)(get_cyclecount() - attachtime);
	random_harvest_direct(&attachentropy, sizeof(attachentropy), RANDOM_ATTACH);
	device_sysctl_update(dev);
	if (dev->busy)
		dev->state = DS_BUSY;
	else
		dev->state = DS_ATTACHED;
	dev->flags &= ~DF_DONENOMATCH;
	EVENTHANDLER_DIRECT_INVOKE(device_attach, dev);
	devadded(dev);
	return (0);
}

/**
 * @brief Detach a driver from a device