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Commit 802d8b49 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM / Domains: Introduce simplified power on routine for system resume 



Introduce function pm_genpd_sync_poweron() for restoring domain power
during resume from system suspend and hibernation.  It can be much
simpler than pm_genpd_poweron(), because it doesn't have to care
about locking and it can skip many checks done by the latter.

Modify pm_genpd_resume_noirq() and pm_genpd_restore_noirq() to use
the new function.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 4cbe5a55

drivers/base/power/domain.c

+30 −4
Original line number Diff line number Diff line
@@ -776,6 +776,32 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd) 
	}

}



/**

 * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.

 * @genpd: PM domain to power on.

 *

 * This function is only called in "noirq" stage of system power transitions, so

 * it need not acquire locks (all of the "noirq" callbacks are executed

 * sequentially, so it is guaranteed that it will never run twice in parallel).

 */

static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)

{

	struct gpd_link *link;



	if (genpd->status != GPD_STATE_POWER_OFF)

		return;



	list_for_each_entry(link, &genpd->slave_links, slave_node) {

		pm_genpd_sync_poweron(link->master);

		genpd_sd_counter_inc(link->master);

	}



	if (genpd->power_on)

		genpd->power_on(genpd);



	genpd->status = GPD_STATE_ACTIVE;

}



/**

 * resume_needed - Check whether to resume a device before system suspend.

 * @dev: Device to check.
@@ -979,7 +1005,7 @@ static int pm_genpd_resume_noirq(struct device *dev) 
	 * guaranteed that this function will never run twice in parallel for

	 * the same PM domain, so it is not necessary to use locking here.

	 */

	pm_genpd_poweron(genpd);

	pm_genpd_sync_poweron(genpd);

	genpd->suspended_count--;



	return genpd_start_dev(genpd, dev);
@@ -1186,8 +1212,8 @@ static int pm_genpd_restore_noirq(struct device *dev) 
	if (genpd->suspended_count++ == 0) {

		/*

		 * The boot kernel might put the domain into arbitrary state,

		 * so make it appear as powered off to pm_genpd_poweron(), so

		 * that it tries to power it on in case it was really off.

		 * so make it appear as powered off to pm_genpd_sync_poweron(),

		 * so that it tries to power it on in case it was really off.

		 */

		genpd->status = GPD_STATE_POWER_OFF;

		if (genpd->suspend_power_off) {
@@ -1205,7 +1231,7 @@ static int pm_genpd_restore_noirq(struct device *dev) 
	if (genpd->suspend_power_off)

		return 0;



	pm_genpd_poweron(genpd);

	pm_genpd_sync_poweron(genpd);



	return dev_gpd_data(dev)->always_on ? 0 : genpd_start_dev(genpd, dev);

}