From 802d8b49a7705298b62ac35a59b867f1288caaf3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 6 Aug 2012 01:39:16 +0200 Subject: [PATCH] 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: Rafael J. Wysocki --- drivers/base/power/domain.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index ba3487c..55c39f5 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -777,6 +777,32 @@ 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. * @genpd: PM domain the device belongs to. @@ -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); } -- 2.7.4