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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM list <linux-pm@vger.kernel.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH 2/5] cpufreq: governor: Check transition latecy at init time only
Date: Sat, 14 May 2016 01:00:28 +0200	[thread overview]
Message-ID: <8685194.VWxfunzal1@vostro.rjw.lan> (raw)
In-Reply-To: <10707470.yIcqGAzuFY@vostro.rjw.lan>

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It is not necessary to check the governor's max_transition_latency
attribute every time cpufreq_governor() runs, so check it only if
the event argument is CPUFREQ_GOV_POLICY_INIT.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpufreq/cpufreq.c |   25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -2011,23 +2011,24 @@ static int cpufreq_governor(struct cpufr
 	if (!policy->governor)
 		return -EINVAL;
 
-	if (policy->governor->max_transition_latency &&
-	    policy->cpuinfo.transition_latency >
-	    policy->governor->max_transition_latency) {
-		struct cpufreq_governor *gov = cpufreq_fallback_governor();
+	if (event == CPUFREQ_GOV_POLICY_INIT) {
+		if (policy->governor->max_transition_latency &&
+		    policy->cpuinfo.transition_latency >
+		    policy->governor->max_transition_latency) {
+			struct cpufreq_governor *gov = cpufreq_fallback_governor();
 
-		if (gov) {
-			pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
-				policy->governor->name, gov->name);
-			policy->governor = gov;
-		} else {
-			return -EINVAL;
+			if (gov) {
+				pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
+					policy->governor->name, gov->name);
+				policy->governor = gov;
+			} else {
+				return -EINVAL;
+			}
 		}
-	}
 
-	if (event == CPUFREQ_GOV_POLICY_INIT)
 		if (!try_module_get(policy->governor->owner))
 			return -EINVAL;
+	}
 
 	pr_debug("%s: for CPU %u, event %u\n", __func__, policy->cpu, event);
 

  parent reply	other threads:[~2016-05-13 23:00 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-13 22:58 [PATCH 0/5] cpufreq: governor: Rework API to use callbacks instead of events Rafael J. Wysocki
2016-05-13 22:59 ` [PATCH 1/5] cpufreq: governor: CPUFREQ_GOV_LIMITS never fails Rafael J. Wysocki
2016-05-13 23:00 ` Rafael J. Wysocki [this message]
2016-05-13 23:01 ` [PATCH 3/5] cpufreq: governor: Simplify performance and powersave governors Rafael J. Wysocki
2016-05-13 23:01 ` [PATCH 4/5] cpufreq: Split cpufreq_governor() into simpler functions Rafael J. Wysocki
2016-05-13 23:02 ` [PATCH 5/5] cpufreq: governor: Get rid of governor events Rafael J. Wysocki
2016-05-16  4:54   ` Viresh Kumar
2016-05-16  4:55 ` [PATCH 0/5] cpufreq: governor: Rework API to use callbacks instead of events Viresh Kumar

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