Commit 975e83cf authored Jul 14, 2017 by Sudeep Holla Committed by Rafael J. Wysocki Jul 19, 2017

PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present



If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach
may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets
the PM domain for the device unconditionally.

When subsequent attempts are made to call genpd_dev_pm_attach, it may
return -EEXISTS checking dev->pm_domain without re-attempting to call
attach_dev or power_on.

platform_drv_probe then attempts to call drv->probe as the return value
-EEXIST != -EPROBE_DEFER, which may end up in a situation where the
device is accessed without it's power domain switched on.

Fixes: f104e1e5 (PM / Domains: Re-order initialization of generic_pm_domain_data)
Cc: 4.4+ <stable@vger.kernel.org> # v4.4+
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent af3eb274

drivers/base/power/domain.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1222,8 +1222,6 @@ static struct generic_pm_domain_data genpd_alloc_dev_data(struct device dev,

		spin_unlock_irq(&dev->power.lock);

		dev_pm_domain_set(dev, &genpd->domain);

		return gpd_data;

		err_free:
		@@ -1237,8 +1235,6 @@ static struct generic_pm_domain_data genpd_alloc_dev_data(struct device dev,
		static void genpd_free_dev_data(struct device *dev,
		struct generic_pm_domain_data *gpd_data)
		{
		dev_pm_domain_set(dev, NULL);

		spin_lock_irq(&dev->power.lock);

		dev->power.subsys_data->domain_data = NULL;
		@@ -1275,6 +1271,8 @@ static int genpd_add_device(struct generic_pm_domain genpd, struct device dev,
		if (ret)
		goto out;

		dev_pm_domain_set(dev, &genpd->domain);

		genpd->device_count++;
		genpd->max_off_time_changed = true;

		@@ -1336,6 +1334,8 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
		if (genpd->detach_dev)
		genpd->detach_dev(genpd, dev);

		dev_pm_domain_set(dev, NULL);

		list_del_init(&pdd->list_node);

		genpd_unlock(genpd);