From: Junjie Wu <junjiew@codeaurora.org>
Date: Fri, 15 Aug 2014 23:34:37 +0000 (-0700)
Subject: cpufreq: interactive: Round up timer_rate to match jiffy
X-Git-Tag: firefly_0821_release~2958^2~244
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4db1f0ac8761fc30d4e1230939d623a52517bdcc;p=firefly-linux-kernel-4.4.55.git

cpufreq: interactive: Round up timer_rate to match jiffy

Timers are scheduled in unit of jiffies. Round up timer_rate so that
it matches the actual sampling period.

Change-Id: I88386a5a448e40333f9a9b9f0cf72af58cb54656
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
---

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 49f206e48aa3..6bbcc905bb3e 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -855,12 +855,18 @@ static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 		const char *buf, size_t count)
 {
 	int ret;
-	unsigned long val;
+	unsigned long val, val_round;
 
 	ret = strict_strtoul(buf, 0, &val);
 	if (ret < 0)
 		return ret;
-	tunables->timer_rate = val;
+
+	val_round = jiffies_to_usecs(usecs_to_jiffies(val));
+	if (val != val_round)
+		pr_warn("timer_rate not aligned to jiffy. Rounded up to %lu\n",
+			val_round);
+
+	tunables->timer_rate = val_round;
 	return count;
 }