From: Todd Poynor <toddpoynor@google.com>
Date: Sun, 23 Dec 2012 20:28:49 +0000 (-0800)
Subject: cpufreq: interactive: don't handle transition notification if not enabled
X-Git-Tag: firefly_0821_release~2958^2~275
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=06371b575fa7823a9a95fbf27f82b4a706e7847e;p=firefly-linux-kernel-4.4.55.git

cpufreq: interactive: don't handle transition notification if not enabled

If multiple governors are in use then avoid processing frequency transition
notifications for CPUs on which the interactive governor is not enabled.

Change-Id: Ibd75255b921d887501a64774a8c4f62302f2d4e4
Reported-by: Francisco Franco <francisco.franco@cloudcar.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
---

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index c8358a3b5454..51c34bf9c173 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -552,6 +552,12 @@ static int cpufreq_interactive_notifier(
 
 	if (val == CPUFREQ_POSTCHANGE) {
 		pcpu = &per_cpu(cpuinfo, freq->cpu);
+		if (!down_read_trylock(&pcpu->enable_sem))
+			return 0;
+		if (!pcpu->governor_enabled) {
+			up_read(&pcpu->enable_sem);
+			return 0;
+		}
 
 		for_each_cpu(cpu, pcpu->policy->cpus) {
 			struct cpufreq_interactive_cpuinfo *pjcpu =
@@ -560,8 +566,9 @@ static int cpufreq_interactive_notifier(
 			update_load(cpu);
 			spin_unlock(&pjcpu->load_lock);
 		}
-	}
 
+		up_read(&pcpu->enable_sem);
+	}
 	return 0;
 }