[PATCH V5 03/10] PM / OPP: Don't use OPP structure outside of rcu protected section

[Viresh Kumar]

The OPP structure must not be used out of the rcu protected section.
Cache the values to be used in separate variables instead.

Cc:  # v4.6+ <sta...@vger.kernel.org>
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
Reviewed-by: Stephen Boyd <sb...@codeaurora.org>
Tested-by: Dave Gerlach <d-gerl...@ti.com>
---
 drivers/base/power/opp/core.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 4c7c6da7a989..056527a3fb4e 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -584,6 +584,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
        struct clk *clk;
        unsigned long freq, old_freq;
        unsigned long u_volt, u_volt_min, u_volt_max;
+       unsigned long old_u_volt, old_u_volt_min, old_u_volt_max;
        int ret;
 
        if (unlikely(!target_freq)) {
@@ -633,6 +634,14 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
                return ret;
        }
 
+       if (IS_ERR(old_opp)) {
+               old_u_volt = 0;
+       } else {
+               old_u_volt = old_opp->u_volt;
+               old_u_volt_min = old_opp->u_volt_min;
+               old_u_volt_max = old_opp->u_volt_max;
+       }
+
        u_volt = opp->u_volt;
        u_volt_min = opp->u_volt_min;
        u_volt_max = opp->u_volt_max;
@@ -677,9 +686,10 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long 
target_freq)
                        __func__, old_freq);
 restore_voltage:
        /* This shouldn't harm even if the voltages weren't updated earlier */
-       if (!IS_ERR(old_opp))
-               _set_opp_voltage(dev, reg, old_opp->u_volt,
-                                old_opp->u_volt_min, old_opp->u_volt_max);
+       if (old_u_volt) {
+               _set_opp_voltage(dev, reg, old_u_volt, old_u_volt_min,
+                                old_u_volt_max);
+       }
 
        return ret;
 }
-- 
2.7.1.410.g6faf27b