PM / Domains: Make pm_genpd_poweron() always survive parent removal
If pm_genpd_remove_subdomain() is called to remove a PM domain's
subdomain and pm_genpd_poweron() is called for that subdomain at
the same time, and the pm_genpd_poweron() called by it recursively
for the parent returns an error, the first pm_genpd_poweron()'s
error code path will attempt to decrement the subdomain counter of
a PM domain that it's not a subdomain of any more.
Rearrange the code in pm_genpd_poweron() to prevent this from
happening.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index ef25b6f..dc423a9 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -89,12 +89,14 @@
*/
int pm_genpd_poweron(struct generic_pm_domain *genpd)
{
- struct generic_pm_domain *parent = genpd->parent;
+ struct generic_pm_domain *parent;
int ret = 0;
- start:
mutex_lock(&genpd->lock);
+ parent = genpd->parent;
+
+ start:
if (genpd->status == GPD_STATE_ACTIVE
|| (genpd->prepared_count > 0 && genpd->suspend_power_off))
goto out;
@@ -110,29 +112,34 @@
mutex_unlock(&genpd->lock);
ret = pm_genpd_poweron(parent);
- if (ret) {
- genpd_sd_counter_dec(parent);
- return ret;
- }
+
+ mutex_lock(&genpd->lock);
+
+ if (ret)
+ goto err;
parent = NULL;
goto start;
}
- if (genpd->power_on)
+ if (genpd->power_on) {
ret = genpd->power_on(genpd);
-
- if (ret) {
- if (genpd->parent)
- genpd_sd_counter_dec(genpd->parent);
- } else {
- genpd_set_active(genpd);
+ if (ret)
+ goto err;
}
+ genpd_set_active(genpd);
+
out:
mutex_unlock(&genpd->lock);
return ret;
+
+ err:
+ if (genpd->parent)
+ genpd_sd_counter_dec(genpd->parent);
+
+ goto out;
}
#endif /* CONFIG_PM */