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-rw-r--r--drivers/base/power/domain.c30
-rw-r--r--include/linux/pm_domain.h2
2 files changed, 21 insertions, 11 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 1c374579407c..20e2b52d9c9c 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -29,10 +29,20 @@ static struct generic_pm_domain *dev_to_genpd(struct device *dev)
return pd_to_genpd(dev->pm_domain);
}
-static void genpd_sd_counter_dec(struct generic_pm_domain *genpd)
+static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
{
- if (!WARN_ON(genpd->sd_count == 0))
- genpd->sd_count--;
+ bool ret = false;
+
+ if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
+ ret = !!atomic_dec_and_test(&genpd->sd_count);
+
+ return ret;
+}
+
+static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
+{
+ atomic_inc(&genpd->sd_count);
+ smp_mb__after_atomic_inc();
}
static void genpd_acquire_lock(struct generic_pm_domain *genpd)
@@ -118,7 +128,7 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd)
genpd_set_active(genpd);
if (parent)
- parent->sd_count++;
+ genpd_sd_counter_inc(parent);
out:
mutex_unlock(&genpd->lock);
@@ -254,7 +264,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
|| genpd->resume_count > 0)
return 0;
- if (genpd->sd_count > 0)
+ if (atomic_read(&genpd->sd_count) > 0)
return -EBUSY;
not_suspended = 0;
@@ -325,8 +335,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
genpd->status = GPD_STATE_POWER_OFF;
if (parent) {
- genpd_sd_counter_dec(parent);
- if (parent->sd_count == 0)
+ if (genpd_sd_counter_dec(parent))
genpd_queue_power_off_work(parent);
genpd_release_lock(parent);
@@ -506,7 +515,8 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
if (genpd->status == GPD_STATE_POWER_OFF)
return;
- if (genpd->suspended_count != genpd->device_count || genpd->sd_count > 0)
+ if (genpd->suspended_count != genpd->device_count
+ || atomic_read(&genpd->sd_count) > 0)
return;
if (genpd->power_off)
@@ -1167,7 +1177,7 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
list_add_tail(&new_subdomain->sd_node, &genpd->sd_list);
new_subdomain->parent = genpd;
if (subdomain->status != GPD_STATE_POWER_OFF)
- genpd->sd_count++;
+ genpd_sd_counter_inc(genpd);
out:
mutex_unlock(&new_subdomain->lock);
@@ -1242,7 +1252,7 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
genpd->gov = gov;
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
genpd->in_progress = 0;
- genpd->sd_count = 0;
+ atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
init_waitqueue_head(&genpd->status_wait_queue);
genpd->poweroff_task = NULL;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index f9ec1736a116..81c5782d90a3 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -33,7 +33,7 @@ struct generic_pm_domain {
struct dev_power_governor *gov;
struct work_struct power_off_work;
unsigned int in_progress; /* Number of devices being suspended now */
- unsigned int sd_count; /* Number of subdomains with power "on" */
+ atomic_t sd_count; /* Number of subdomains with power "on" */
enum gpd_status status; /* Current state of the domain */
wait_queue_head_t status_wait_queue;
struct task_struct *poweroff_task; /* Powering off task */