Patch "PM / OPP: Don't use OPP structure outside of rcu protected section" has been added to the 4.9-stable tree

Patch "PM / OPP: Don't use OPP structure outside of rcu protected section" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pm-opp-don-t-use-opp-structure-outside-of-rcu-protected-section.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From dc39d06fcd7a4a82d72eae7b71e94e888b96d29e Mon Sep 17 00:00:00 2001
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: Thu, 1 Dec 2016 16:28:16 +0530
Subject: PM / OPP: Don't use OPP structure outside of rcu protected section

From: Viresh Kumar <viresh.kumar@linaro.org>

commit dc39d06fcd7a4a82d72eae7b71e94e888b96d29e upstream.

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

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/power/opp/core.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

--- 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 *d
 	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 *d
 		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 @@ restore_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;
 }


Patches currently in stable-queue which might be from viresh.kumar@linaro.org are

queue-4.9/pm-opp-don-t-use-opp-structure-outside-of-rcu-protected-section.patch
queue-4.9/pm-opp-pass-opp_table-to-dev_pm_opp_put_regulator.patch