static int genpd_power_off()

in power/domain.c [613:689]

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

static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
			   unsigned int depth)
{
	struct pm_domain_data *pdd;
	struct gpd_link *link;
	unsigned int not_suspended = 0;
	int ret;

	/*
	 * Do not try to power off the domain in the following situations:
	 * (1) The domain is already in the "power off" state.
	 * (2) System suspend is in progress.
	 */
	if (!genpd_status_on(genpd) || genpd->prepared_count > 0)
		return 0;

	/*
	 * Abort power off for the PM domain in the following situations:
	 * (1) The domain is configured as always on.
	 * (2) When the domain has a subdomain being powered on.
	 */
	if (genpd_is_always_on(genpd) ||
			genpd_is_rpm_always_on(genpd) ||
			atomic_read(&genpd->sd_count) > 0)
		return -EBUSY;

	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
		enum pm_qos_flags_status stat;

		stat = dev_pm_qos_flags(pdd->dev, PM_QOS_FLAG_NO_POWER_OFF);
		if (stat > PM_QOS_FLAGS_NONE)
			return -EBUSY;

		/*
		 * Do not allow PM domain to be powered off, when an IRQ safe
		 * device is part of a non-IRQ safe domain.
		 */
		if (!pm_runtime_suspended(pdd->dev) ||
			irq_safe_dev_in_no_sleep_domain(pdd->dev, genpd))
			not_suspended++;
	}

	if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
		return -EBUSY;

	if (genpd->gov && genpd->gov->power_down_ok) {
		if (!genpd->gov->power_down_ok(&genpd->domain))
			return -EAGAIN;
	}

	/* Default to shallowest state. */
	if (!genpd->gov)
		genpd->state_idx = 0;

	/* Don't power off, if a child domain is waiting to power on. */
	if (atomic_read(&genpd->sd_count) > 0)
		return -EBUSY;

	ret = _genpd_power_off(genpd, true);
	if (ret) {
		genpd->states[genpd->state_idx].rejected++;
		return ret;
	}

	genpd->status = GENPD_STATE_OFF;
	genpd_update_accounting(genpd);
	genpd->states[genpd->state_idx].usage++;

	list_for_each_entry(link, &genpd->child_links, child_node) {
		genpd_sd_counter_dec(link->parent);
		genpd_lock_nested(link->parent, depth + 1);
		genpd_power_off(link->parent, false, depth + 1);
		genpd_unlock(link->parent);
	}

	return 0;
}