4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sudeep Holla <Sudeep.Holla@xxxxxxx>
commit 975e83cfb8dc16e7a2fdc58188c77c0c605876c2 upstream.
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: f104e1e5ef57 (PM / Domains: Re-order initialization of generic_pm_domain_data)
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/power/domain.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1188,7 +1188,6 @@ static struct generic_pm_domain_data *ge
}
dev->power.subsys_data->domain_data = &gpd_data->base;
- dev->pm_domain = &genpd->domain;
spin_unlock_irq(&dev->power.lock);
@@ -1207,7 +1206,6 @@ static void genpd_free_dev_data(struct d
{
spin_lock_irq(&dev->power.lock);
- dev->pm_domain = NULL;
dev->power.subsys_data->domain_data = NULL;
spin_unlock_irq(&dev->power.lock);
@@ -1248,6 +1246,8 @@ int __pm_genpd_add_device(struct generic
if (ret)
goto out;
+ dev->pm_domain = &genpd->domain;
+
genpd->device_count++;
genpd->max_off_time_changed = true;
@@ -1299,6 +1299,8 @@ int pm_genpd_remove_device(struct generi
if (genpd->detach_dev)
genpd->detach_dev(genpd, dev);
+ dev->pm_domain = NULL;
+
list_del_init(&pdd->list_node);
mutex_unlock(&genpd->lock);