PM / OPP: Don't use OPP structure outside of rcu protected section

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

Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 2824d3a5e9f027b53febdc009442b7a196a8e297..6441dfda489f80a404bacd6132d8900b9d98c6bf 100644 (file)
--- 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;
 }