1 files changed, 107 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches-4.9/0050-OPP-Allow-notifiers-to-call-dev_pm_opp_get_-voltage-.patch b/target/linux/ipq806x/patches-4.9/0050-OPP-Allow-notifiers-to-call-dev_pm_opp_get_-voltage-.patch
new file mode 100644
index 0000000000..7b41157fd6
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.9/0050-OPP-Allow-notifiers-to-call-dev_pm_opp_get_-voltage-.patch
@@ -0,0 +1,107 @@
+From 4a17bbfcf72c94b37079e39a7c1e1e8653f7fe92 Mon Sep 17 00:00:00 2001
+From: Stephen Boyd <sboyd@codeaurora.org>
+Date: Fri, 18 Sep 2015 17:52:07 -0700
+Subject: [PATCH 50/69] OPP: Allow notifiers to call dev_pm_opp_get_{voltage,
+ freq} RCU-free
+
+We pass the dev_pm_opp structure to OPP notifiers but the users
+of the notifier need to surround calls to dev_pm_opp_get_*() with
+RCU read locks to avoid lockdep warnings. The notifier is already
+called with the dev_opp's srcu lock held, so it should be safe to
+assume the devm_pm_opp structure is already protected inside the
+notifier. Update the lockdep check for this.
+
+Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
+Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
+Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
+Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
+---
+ drivers/base/power/opp/core.c | 19 ++++++++++---------
+ 1 file changed, 10 insertions(+), 9 deletions(-)
+
+--- a/drivers/base/power/opp/core.c
++++ b/drivers/base/power/opp/core.c
+@@ -32,9 +32,10 @@ LIST_HEAD(opp_tables);
+ /* Lock to allow exclusive modification to the device and opp lists */
+ DEFINE_MUTEX(opp_table_lock);
+ 
+-#define opp_rcu_lockdep_assert()					\
++#define opp_rcu_lockdep_assert(s)					\
+ do {									\
+ 	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
++			 !(s && srcu_read_lock_held(s)) &&		\
+ 			 !lockdep_is_held(&opp_table_lock),		\
+ 			 "Missing rcu_read_lock() or "			\
+ 			 "opp_table_lock protection");			\
+@@ -72,7 +73,7 @@ struct opp_table *_find_opp_table(struct
+ {
+ 	struct opp_table *opp_table;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	if (IS_ERR_OR_NULL(dev)) {
+ 		pr_err("%s: Invalid parameters\n", __func__);
+@@ -106,7 +107,7 @@ unsigned long dev_pm_opp_get_voltage(str
+ 	struct dev_pm_opp *tmp_opp;
+ 	unsigned long v = 0;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	tmp_opp = rcu_dereference(opp);
+ 	if (IS_ERR_OR_NULL(tmp_opp))
+@@ -138,7 +139,7 @@ unsigned long dev_pm_opp_get_freq(struct
+ 	struct dev_pm_opp *tmp_opp;
+ 	unsigned long f = 0;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	tmp_opp = rcu_dereference(opp);
+ 	if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
+@@ -172,7 +173,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_o
+ {
+ 	struct dev_pm_opp *tmp_opp;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	tmp_opp = rcu_dereference(opp);
+ 	if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
+@@ -300,7 +301,7 @@ struct dev_pm_opp *dev_pm_opp_get_suspen
+ {
+ 	struct opp_table *opp_table;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	opp_table = _find_opp_table(dev);
+ 	if (IS_ERR(opp_table) || !opp_table->suspend_opp ||
+@@ -380,7 +381,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ 	struct opp_table *opp_table;
+ 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	opp_table = _find_opp_table(dev);
+ 	if (IS_ERR(opp_table)) {
+@@ -444,7 +445,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ {
+ 	struct opp_table *opp_table;
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	if (!dev || !freq) {
+ 		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
+@@ -486,7 +487,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ 	struct opp_table *opp_table;
+ 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+ 
+-	opp_rcu_lockdep_assert();
++	opp_rcu_lockdep_assert(NULL);
+ 
+ 	if (!dev || !freq) {
+ 		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);