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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-10-21 21:12:15 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-10 12:37:34 +0100
commit874dfb5c6aa3001b8528eb5b0ac57cdabc6a41e8 (patch)
tree82d72cb6f55b19d873eae4d3eb4244627ce42a28
parentfbfca92c7840db5f4a980b111789ab0a7af745ef (diff)
PM: runtime: Drop runtime PM references to supplier on link removal
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>
-rw-r--r--drivers/base/core.c6
-rw-r--r--drivers/base/power/runtime.c21
-rw-r--r--include/linux/pm_runtime.h4
3 files changed, 24 insertions, 7 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 0fde3e9e63ee..ddfbd62d8bfc 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -454,8 +454,7 @@ static void __device_link_del(struct kref *kref)
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);
@@ -469,8 +468,7 @@ static void __device_link_del(struct kref *kref)
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);
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 4244e22e4b40..159e9c6e16c2 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1702,7 +1702,7 @@ void pm_runtime_new_link(struct device *dev)
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);
@@ -1710,6 +1710,25 @@ void pm_runtime_drop_link(struct device *dev)
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 &&
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 22af69d237a6..d805fb1ae880 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -58,7 +58,7 @@ extern void pm_runtime_clean_up_links(struct device *dev);
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);
static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
{
@@ -177,7 +177,7 @@ static inline void pm_runtime_clean_up_links(struct device *dev) {}
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 */