@@ -934,11 +934,12 @@ static void genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
* The domain is already in the "power off" state.
* System suspend is in progress.
* The domain is configured as always on.
+ * The domain was on at boot and still need to stay on.
* The domain has a subdomain being powered on.
*/
if (!genpd_status_on(genpd) || genpd->prepared_count > 0 ||
genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd) ||
- atomic_read(&genpd->sd_count) > 0)
+ genpd->stay_on || atomic_read(&genpd->sd_count) > 0)
return;
/*
@@ -1349,8 +1350,12 @@ static int __init genpd_power_off_unused(void)
pr_info("genpd: Disabling unused power domains\n");
mutex_lock(&gpd_list_lock);
- list_for_each_entry(genpd, &gpd_list, gpd_list_node)
+ list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
+ genpd_lock(genpd);
+ genpd->stay_on = false;
+ genpd_unlock(genpd);
genpd_queue_power_off_work(genpd);
+ }
mutex_unlock(&gpd_list_lock);
@@ -2375,6 +2380,7 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GENPD_STATE_OFF : GENPD_STATE_ON;
+ genpd->stay_on = !is_off;
genpd->sync_state = GENPD_SYNC_STATE_OFF;
genpd->device_count = 0;
genpd->provider = NULL;
@@ -199,6 +199,7 @@ struct generic_pm_domain {
unsigned int performance_state; /* Aggregated max performance state */
cpumask_var_t cpus; /* A cpumask of the attached CPUs */
bool synced_poweroff; /* A consumer needs a synced poweroff */
+ bool stay_on; /* Stay powered-on during boot. */
enum genpd_sync_state sync_state; /* How sync_state is managed. */
int (*power_off)(struct generic_pm_domain *domain);
int (*power_on)(struct generic_pm_domain *domain);
Powering-off a genpd that was on during boot, before all of its consumer devices have been probed, is certainly prone to problems. As a step to improve this situation, let's prevent these genpds from being powered-off until genpd_power_off_unused() gets called, which is a late_initcall_sync(). Note that, this still doesn't guarantee that all the consumer devices has been probed before we allow to power-off the genpds. Yet, this should be a step in the right direction. Suggested-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/pmdomain/core.c | 10 ++++++++-- include/linux/pm_domain.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-)