PM / Domains: Make device removal more straightforward

The removal of a device from a PM domain doesn't have to browse
the domain's device list, because it can check directly if the
device belongs to the given domain.  Moreover, it should clear
the domain_data pointer in dev->power.subsys_data, because
dev_pm_put_subsys_data(dev) may not remove dev->power.subsys_data
and the stale domain data pointer may cause problems to happen.

Rework pm_genpd_remove_device() taking the above observations into
account.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 45c2b7f..6ae5672 100644 (file)
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1279,11 +1279,13 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
                           struct device *dev)
 {
        struct pm_domain_data *pdd;
-       int ret = -EINVAL;
+       int ret = 0;
 
        dev_dbg(dev, "%s()\n", __func__);
 
-       if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
+       if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
+           ||  IS_ERR_OR_NULL(dev->pm_domain)
+           ||  pd_to_genpd(dev->pm_domain) != genpd)
                return -EINVAL;
 
        genpd_acquire_lock(genpd);
@@ -1293,21 +1295,14 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
                goto out;
        }
 
-       list_for_each_entry(pdd, &genpd->dev_list, list_node) {
-               if (pdd->dev != dev)
-                       continue;
-
-               list_del_init(&pdd->list_node);
-               pdd->dev = NULL;
-               dev_pm_put_subsys_data(dev);
-               dev->pm_domain = NULL;
-               kfree(to_gpd_data(pdd));
-
-               genpd->device_count--;
+       dev->pm_domain = NULL;
+       pdd = dev->power.subsys_data->domain_data;
+       list_del_init(&pdd->list_node);
+       dev->power.subsys_data->domain_data = NULL;
+       dev_pm_put_subsys_data(dev);
+       kfree(to_gpd_data(pdd));
 
-               ret = 0;
-               break;
-       }
+       genpd->device_count--;
 
  out:
        genpd_release_lock(genpd);