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-rw-r--r--drivers/base/power/domain.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 5db704f02e71..c87588c21700 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -636,6 +636,18 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
atomic_read(&genpd->sd_count) > 0)
return -EBUSY;
+ /*
+ * The children must be in their deepest (powered-off) states to allow
+ * the parent to be powered off. Note that, there's no need for
+ * additional locking, as powering on a child, requires the parent's
+ * lock to be acquired first.
+ */
+ list_for_each_entry(link, &genpd->parent_links, parent_node) {
+ struct generic_pm_domain *child = link->child;
+ if (child->state_idx < child->state_count - 1)
+ return -EBUSY;
+ }
+
list_for_each_entry(pdd, &genpd->dev_list, list_node) {
enum pm_qos_flags_status stat;
@@ -1073,6 +1085,13 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
|| atomic_read(&genpd->sd_count) > 0)
return;
+ /* Check that the children are in their deepest (powered-off) state. */
+ list_for_each_entry(link, &genpd->parent_links, parent_node) {
+ struct generic_pm_domain *child = link->child;
+ if (child->state_idx < child->state_count - 1)
+ return;
+ }
+
/* Choose the deepest state when suspending */
genpd->state_idx = genpd->state_count - 1;
if (_genpd_power_off(genpd, false))