linux-kernel - [RFC PATCH 11/19] cpufreq: assert policy->rwsem is held in __cpufreq

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Date:	Mon, 11 Jan 2016 17:35:52 +0000
From:	Juri Lelli <juri.lelli@....com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-pm@...r.kernel.org, peterz@...radead.org, rjw@...ysocki.net,
	viresh.kumar@...aro.org, mturquette@...libre.com,
	steve.muckle@...aro.org, vincent.guittot@...aro.org,
	morten.rasmussen@....com, dietmar.eggemann@....com,
	juri.lelli@....com
Subject: [RFC PATCH 11/19] cpufreq: assert policy->rwsem is held in __cpufreq_governor

__cpufreq_governor works on policy, so policy->rwsem has to be held.
Add assertion for such condition.

Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Juri Lelli <juri.lelli@....com>
---
 drivers/cpufreq/cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f1f9fbc..e7fc5c9 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1950,6 +1950,9 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
 	/* Don't start any governor operations if we are entering suspend */
 	if (cpufreq_suspended)
 		return 0;
+
+	lockdep_assert_held(&policy->rwsem);
+
 	/*
 	 * Governor might not be initiated here if ACPI _PPC changed
 	 * notification happened, so check it.
-- 
2.2.2