target/linux/ipq806x/patches-4.9/0050-OPP-Allow-notifiers-to-call-dev_pm_opp_get_-voltage-.patch

   1 From 4a17bbfcf72c94b37079e39a7c1e1e8653f7fe92 Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Fri, 18 Sep 2015 17:52:07 -0700
   4 Subject: [PATCH 50/69] OPP: Allow notifiers to call dev_pm_opp_get_{voltage,
   5  freq} RCU-free
   6
   7 We pass the dev_pm_opp structure to OPP notifiers but the users
   8 of the notifier need to surround calls to dev_pm_opp_get_*() with
   9 RCU read locks to avoid lockdep warnings. The notifier is already
  10 called with the dev_opp's srcu lock held, so it should be safe to
  11 assume the devm_pm_opp structure is already protected inside the
  12 notifier. Update the lockdep check for this.
  13
  14 Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
  15 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  16 Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
  17 Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
  18 ---
  19  drivers/base/power/opp/core.c | 19 ++++++++++---------
  20  1 file changed, 10 insertions(+), 9 deletions(-)
  21
  22 --- a/drivers/base/power/opp/core.c
  23 +++ b/drivers/base/power/opp/core.c
  24 @@ -32,9 +32,10 @@ LIST_HEAD(opp_tables);
  25  /* Lock to allow exclusive modification to the device and opp lists */
  26  DEFINE_MUTEX(opp_table_lock);
  27
  28 -#define opp_rcu_lockdep_assert()                                       \
  29 +#define opp_rcu_lockdep_assert(s)                                      \
  30  do {                                                                   \
  31         RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&                       \
  32 +                        !(s && srcu_read_lock_held(s)) &&              \
  33                          !lockdep_is_held(&opp_table_lock),             \
  34                          "Missing rcu_read_lock() or "                  \
  35                          "opp_table_lock protection");                  \
  36 @@ -72,7 +73,7 @@ struct opp_table *_find_opp_table(struct
  37  {
  38         struct opp_table *opp_table;
  39
  40 -       opp_rcu_lockdep_assert();
  41 +       opp_rcu_lockdep_assert(NULL);
  42
  43         if (IS_ERR_OR_NULL(dev)) {
  44                 pr_err("%s: Invalid parameters\n", __func__);
  45 @@ -106,7 +107,7 @@ unsigned long dev_pm_opp_get_voltage(str
  46         struct dev_pm_opp *tmp_opp;
  47         unsigned long v = 0;
  48
  49 -       opp_rcu_lockdep_assert();
  50 +       opp_rcu_lockdep_assert(NULL);
  51
  52         tmp_opp = rcu_dereference(opp);
  53         if (IS_ERR_OR_NULL(tmp_opp))
  54 @@ -138,7 +139,7 @@ unsigned long dev_pm_opp_get_freq(struct
  55         struct dev_pm_opp *tmp_opp;
  56         unsigned long f = 0;
  57
  58 -       opp_rcu_lockdep_assert();
  59 +       opp_rcu_lockdep_assert(NULL);
  60
  61         tmp_opp = rcu_dereference(opp);
  62         if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
  63 @@ -172,7 +173,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_o
  64  {
  65         struct dev_pm_opp *tmp_opp;
  66
  67 -       opp_rcu_lockdep_assert();
  68 +       opp_rcu_lockdep_assert(NULL);
  69
  70         tmp_opp = rcu_dereference(opp);
  71         if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
  72 @@ -300,7 +301,7 @@ struct dev_pm_opp *dev_pm_opp_get_suspen
  73  {
  74         struct opp_table *opp_table;
  75
  76 -       opp_rcu_lockdep_assert();
  77 +       opp_rcu_lockdep_assert(NULL);
  78
  79         opp_table = _find_opp_table(dev);
  80         if (IS_ERR(opp_table) || !opp_table->suspend_opp ||
  81 @@ -380,7 +381,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
  82         struct opp_table *opp_table;
  83         struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
  84
  85 -       opp_rcu_lockdep_assert();
  86 +       opp_rcu_lockdep_assert(NULL);
  87
  88         opp_table = _find_opp_table(dev);
  89         if (IS_ERR(opp_table)) {
  90 @@ -444,7 +445,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
  91  {
  92         struct opp_table *opp_table;
  93
  94 -       opp_rcu_lockdep_assert();
  95 +       opp_rcu_lockdep_assert(NULL);
  96
  97         if (!dev || !freq) {
  98                 dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
  99 @@ -486,7 +487,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
 100         struct opp_table *opp_table;
 101         struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
 102
 103 -       opp_rcu_lockdep_assert();
 104 +       opp_rcu_lockdep_assert(NULL);
 105
 106         if (!dev || !freq) {
 107                 dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);