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

   1 From dafae9c5b39e2871bfd8db0b4bad6e850e42ef49 Mon Sep 17 00:00:00 2001
   2 From: Georgi Djakov <georgi.djakov@linaro.org>
   3 Date: Wed, 13 Jan 2016 15:10:25 +0200
   4 Subject: cpufreq-dt: Add missing rcu_read_lock() for find_device_opp()
   5
   6 The function dev_pm_opp_get_notifier() must be called with held
   7 rcu_read_lock. In order to keep the pointer valid, add rcu_read_lock().
   8
   9 Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
  10 ---
  11  drivers/cpufreq/cpufreq-dt.c | 3 +++
  12  1 file changed, 3 insertions(+)
  13
  14 --- a/drivers/cpufreq/cpufreq-dt.c
  15 +++ b/drivers/cpufreq/cpufreq-dt.c
  16 @@ -359,14 +359,17 @@ static int cpufreq_init(struct cpufreq_p
  17
  18         mutex_init(&priv->lock);
  19
  20 +       rcu_read_lock();
  21         opp_srcu_head = dev_pm_opp_get_notifier(cpu_dev);
  22         if (IS_ERR(opp_srcu_head)) {
  23                 ret = PTR_ERR(opp_srcu_head);
  24 +               rcu_read_unlock();
  25                 goto out_free_priv;
  26         }
  27
  28         priv->opp_nb.notifier_call = opp_notifier;
  29         ret = srcu_notifier_chain_register(opp_srcu_head, &priv->opp_nb);
  30 +       rcu_read_unlock();
  31         if (ret)
  32                 goto out_free_priv;
  33