ipq806x: switch to generic cpufreq driver cpufreq-dt

[openwrt/openwrt.git] / target / linux / ipq806x / patches-4.4 / 174-cpufreq-dt-Add-missing-rcu_read_lock-for-find_device_opp.patch

diff --git a/target/linux/ipq806x/patches-4.4/174-cpufreq-dt-Add-missing-rcu_read_lock-for-find_device_opp.patch b/target/linux/ipq806x/patches-4.4/174-cpufreq-dt-Add-missing-rcu_read_lock-for-find_device_opp.patch
new file mode 100644 (file)
index 0000000..1242721
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.4/174-cpufreq-dt-Add-missing-rcu_read_lock-for-find_device_opp.patch
@@ -0,0 +1,33 @@
+From dafae9c5b39e2871bfd8db0b4bad6e850e42ef49 Mon Sep 17 00:00:00 2001
+From: Georgi Djakov <georgi.djakov@linaro.org>
+Date: Wed, 13 Jan 2016 15:10:25 +0200
+Subject: cpufreq-dt: Add missing rcu_read_lock() for find_device_opp()
+
+The function dev_pm_opp_get_notifier() must be called with held
+rcu_read_lock. In order to keep the pointer valid, add rcu_read_lock().
+
+Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
+---
+ drivers/cpufreq/cpufreq-dt.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/drivers/cpufreq/cpufreq-dt.c
++++ b/drivers/cpufreq/cpufreq-dt.c
+@@ -359,14 +359,17 @@ static int cpufreq_init(struct cpufreq_p
+ 
+       mutex_init(&priv->lock);
+ 
++      rcu_read_lock();
+       opp_srcu_head = dev_pm_opp_get_notifier(cpu_dev);
+       if (IS_ERR(opp_srcu_head)) {
+               ret = PTR_ERR(opp_srcu_head);
++              rcu_read_unlock();
+               goto out_free_priv;
+       }
+ 
+       priv->opp_nb.notifier_call = opp_notifier;
+       ret = srcu_notifier_chain_register(opp_srcu_head, &priv->opp_nb);
++      rcu_read_unlock();
+       if (ret)
+               goto out_free_priv;
+