From: Rafael J. Wysocki rafael.j.wysocki@intel.com
commit e0e398e204634db8fb71bd89cf2f6e3e5bd09b51 upstream.
While removing a device link, drop the supplier device's runtime PM usage counter as many times as needed to drop all of the runtime PM references to it from the consumer in addition to dropping the consumer's link count.
Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Cc: 5.1+ stable@vger.kernel.org # 5.1+ Tested-by: Xiang Chen chenxiang66@hisilicon.com Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/base/core.c | 6 ++---- drivers/base/power/runtime.c | 21 ++++++++++++++++++++- include/linux/pm_runtime.h | 4 ++-- 3 files changed, 24 insertions(+), 7 deletions(-)
--- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -763,8 +763,7 @@ static void __device_link_del(struct kre dev_dbg(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier));
- if (link->flags & DL_FLAG_PM_RUNTIME) - pm_runtime_drop_link(link->consumer); + pm_runtime_drop_link(link);
list_del_rcu(&link->s_node); list_del_rcu(&link->c_node); @@ -778,8 +777,7 @@ static void __device_link_del(struct kre dev_info(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier));
- if (link->flags & DL_FLAG_PM_RUNTIME) - pm_runtime_drop_link(link->consumer); + pm_runtime_drop_link(link);
list_del(&link->s_node); list_del(&link->c_node); --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1729,7 +1729,7 @@ void pm_runtime_new_link(struct device * spin_unlock_irq(&dev->power.lock); }
-void pm_runtime_drop_link(struct device *dev) +static void pm_runtime_drop_link_count(struct device *dev) { spin_lock_irq(&dev->power.lock); WARN_ON(dev->power.links_count == 0); @@ -1737,6 +1737,25 @@ void pm_runtime_drop_link(struct device spin_unlock_irq(&dev->power.lock); }
+/** + * pm_runtime_drop_link - Prepare for device link removal. + * @link: Device link going away. + * + * Drop the link count of the consumer end of @link and decrement the supplier + * device's runtime PM usage counter as many times as needed to drop all of the + * PM runtime reference to it from the consumer. + */ +void pm_runtime_drop_link(struct device_link *link) +{ + if (!(link->flags & DL_FLAG_PM_RUNTIME)) + return; + + pm_runtime_drop_link_count(link->consumer); + + while (refcount_dec_not_one(&link->rpm_active)) + pm_runtime_put(link->supplier); +} + static bool pm_runtime_need_not_resume(struct device *dev) { return atomic_read(&dev->power.usage_count) <= 1 && --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -58,7 +58,7 @@ extern void pm_runtime_clean_up_links(st extern void pm_runtime_get_suppliers(struct device *dev); extern void pm_runtime_put_suppliers(struct device *dev); extern void pm_runtime_new_link(struct device *dev); -extern void pm_runtime_drop_link(struct device *dev); +extern void pm_runtime_drop_link(struct device_link *link);
/** * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. @@ -280,7 +280,7 @@ static inline void pm_runtime_clean_up_l static inline void pm_runtime_get_suppliers(struct device *dev) {} static inline void pm_runtime_put_suppliers(struct device *dev) {} static inline void pm_runtime_new_link(struct device *dev) {} -static inline void pm_runtime_drop_link(struct device *dev) {} +static inline void pm_runtime_drop_link(struct device_link *link) {}
#endif /* !CONFIG_PM */