Merge branch 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm

Pull an operating performance points (OPP) framework fix for 5.12
from Viresh Kumar:

"Fix OPP refcount issue noticed by Beata."

* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  opp: Don't drop extra references to OPPs accidentally

2 files changed, 27 insertions, 23 deletions

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index c2689386a906..1556998425d5 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1492,7 +1492,11 @@ static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
 
 	mutex_lock(&opp_table->lock);
 	list_for_each_entry(temp, &opp_table->opp_list, node) {
-		if (dynamic == temp->dynamic) {
+		/*
+		 * Refcount must be dropped only once for each OPP by OPP core,
+		 * do that with help of "removed" flag.
+		 */
+		if (!temp->removed && dynamic == temp->dynamic) {
 			opp = temp;
 			break;
 		}
@@ -1502,10 +1506,27 @@ static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
 	return opp;
 }
 
-bool _opp_remove_all_static(struct opp_table *opp_table)
+/*
+ * Can't call dev_pm_opp_put() from under the lock as debugfs removal needs to
+ * happen lock less to avoid circular dependency issues. This routine must be
+ * called without the opp_table->lock held.
+ */
+static void _opp_remove_all(struct opp_table *opp_table, bool dynamic)
 {
 	struct dev_pm_opp *opp;
 
+	while ((opp = _opp_get_next(opp_table, dynamic))) {
+		opp->removed = true;
+		dev_pm_opp_put(opp);
+
+		/* Drop the references taken by dev_pm_opp_add() */
+		if (dynamic)
+			dev_pm_opp_put_opp_table(opp_table);
+	}
+}
+
+bool _opp_remove_all_static(struct opp_table *opp_table)
+{
 	mutex_lock(&opp_table->lock);
 
 	if (!opp_table->parsed_static_opps) {
@@ -1520,13 +1541,7 @@ bool _opp_remove_all_static(struct opp_table *opp_table)
 
 	mutex_unlock(&opp_table->lock);
 
-	/*
-	 * Can't remove the OPP from under the lock, debugfs removal needs to
-	 * happen lock less to avoid circular dependency issues.
-	 */
-	while ((opp = _opp_get_next(opp_table, false)))
-		dev_pm_opp_put(opp);
-
+	_opp_remove_all(opp_table, false);
 	return true;
 }
 
@@ -1539,25 +1554,12 @@ bool _opp_remove_all_static(struct opp_table *opp_table)
 void dev_pm_opp_remove_all_dynamic(struct device *dev)
 {
 	struct opp_table *opp_table;
-	struct dev_pm_opp *opp;
-	int count = 0;
 
 	opp_table = _find_opp_table(dev);
 	if (IS_ERR(opp_table))
 		return;
 
-	/*
-	 * Can't remove the OPP from under the lock, debugfs removal needs to
-	 * happen lock less to avoid circular dependency issues.
-	 */
-	while ((opp = _opp_get_next(opp_table, true))) {
-		dev_pm_opp_put(opp);
-		count++;
-	}
-
-	/* Drop the references taken by dev_pm_opp_add() */
-	while (count--)
-		dev_pm_opp_put_opp_table(opp_table);
+	_opp_remove_all(opp_table, true);
 
 	/* Drop the reference taken by _find_opp_table() */
 	dev_pm_opp_put_opp_table(opp_table);
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 50fb9dced3c5..407c3bfe51d9 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -56,6 +56,7 @@ extern struct list_head opp_tables, lazy_opp_tables;
  * @dynamic:	not-created from static DT entries.
  * @turbo:	true if turbo (boost) OPP
  * @suspend:	true if suspend OPP
+ * @removed:	flag indicating that OPP's reference is dropped by OPP core.
  * @pstate: Device's power domain's performance state.
  * @rate:	Frequency in hertz
  * @level:	Performance level
@@ -78,6 +79,7 @@ struct dev_pm_opp {
 	bool dynamic;
 	bool turbo;
 	bool suspend;
+	bool removed;
 	unsigned int pstate;
 	unsigned long rate;
 	unsigned int level;