Blob Blame History Raw
From 11e1a1648298656722fe206a53e555e2e98668ae Mon Sep 17 00:00:00 2001
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Wed, 3 Jul 2019 15:03:14 +0530
Subject: [PATCH] opp: Don't decrement uninitialized list_kref
Git-commit: 11e1a1648298656722fe206a53e555e2e98668ae
Patch-mainline: v5.4-rc1
References: git-fixes

The list_kref was added for static OPPs and to track their users. The
kref is initialized while the static OPPs are added, but removed
unconditionally even if the static OPPs were never added. This causes
refcount mismatch warnings currently.

Fix that by always initializing the kref when the OPP table is first
initialized. The refcount is later incremented only for the second user
onwards.

Fixes: d0e8ae6c26da ("OPP: Create separate kref for static OPPs list")
Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/opp/core.c |  1 +
 drivers/opp/of.c   | 21 ++++-----------------
 2 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 0ee8c0133d3e..9ff0538ee83a 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -988,6 +988,7 @@ static struct opp_table *_allocate_opp_table(struct device *dev, int index)
 	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
 	INIT_LIST_HEAD(&opp_table->opp_list);
 	kref_init(&opp_table->kref);
+	kref_init(&opp_table->list_kref);
 
 	/* Secure the device table modification */
 	list_add(&opp_table->node, &opp_tables);
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index b313aca9894f..698a92c3c17b 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -662,8 +662,6 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 		return 0;
 	}
 
-	kref_init(&opp_table->list_kref);
-
 	/* We have opp-table node now, iterate over it and add OPPs */
 	for_each_available_child_of_node(opp_table->np, np) {
 		opp = _opp_add_static_v2(opp_table, dev, np);
@@ -672,17 +670,15 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
 				ret);
 			of_node_put(np);
-			goto put_list_kref;
+			return ret;
 		} else if (opp) {
 			count++;
 		}
 	}
 
 	/* There should be one of more OPP defined */
-	if (WARN_ON(!count)) {
-		ret = -ENOENT;
-		goto put_list_kref;
-	}
+	if (WARN_ON(!count))
+		return -ENOENT;
 
 	list_for_each_entry(opp, &opp_table->opp_list, node)
 		pstate_count += !!opp->pstate;
@@ -691,8 +687,7 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 	if (pstate_count && pstate_count != count) {
 		dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
 			count, pstate_count);
-		ret = -ENOENT;
-		goto put_list_kref;
+		return -ENOENT;
 	}
 
 	if (pstate_count)
@@ -701,11 +696,6 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
 	opp_table->parsed_static_opps = true;
 
 	return 0;
-
-put_list_kref:
-	_put_opp_list_kref(opp_table);
-
-	return ret;
 }
 
 /* Initializes OPP tables based on old-deprecated bindings */
@@ -731,8 +721,6 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 		return -EINVAL;
 	}
 
-	kref_init(&opp_table->list_kref);
-
 	val = prop->value;
 	while (nr) {
 		unsigned long freq = be32_to_cpup(val++) * 1000;
@@ -742,7 +730,6 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 		if (ret) {
 			dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
 				__func__, freq, ret);
-			_put_opp_list_kref(opp_table);
 			return ret;
 		}
 		nr -= 2;
-- 
2.16.4