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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-03-12 18:47:22 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-03-12 18:47:22 +0100
commit7180323227702b46677e51d0da71f452615efd8c (patch)
treea37e2e2a6457101c31dc2a26b456ee2e70f6d9ec
parentb7dea0cb3d37bc2ee9e7b78722e8729aac7aa1de (diff)
parentbee7359f65af0c67f3c8a39810619d7e517cac9e (diff)
Merge branch 'pm-opp'
* pm-opp: opp: Don't drop extra references to OPPs accidentally
-rw-r--r--drivers/opp/core.c48
-rw-r--r--drivers/opp/opp.h2
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;