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From: Viresh Kumar <viresh.kumar@linaro.org>
To: rjw@sisk.pl
Cc: cpufreq@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linaro-dev@lists.linaro.org, patches@linaro.org,
	pdsw-power-team@arm.com, arvind.chauhan@arm.com,
	Viresh Kumar <viresh.kumar@linaro.org>
Subject: [RFC] cpufreq: Make sure target freq is within limits
Date: Thu, 25 Oct 2012 12:03:34 +0530	[thread overview]
Message-ID: <f0099171c1c4f3048d0f29b7deb42144f26ac5d5.1351146515.git.viresh.kumar@linaro.org> (raw)

Hi Rafael,

__cpufreq_driver_target() must not pass target frequency beyond the limits of
current policy.

Today most of cpufreq platform drivers are doing this check in their target
routines. Why not move it to __cpufreq_driver_target().

I wanted to get your opinion on this before making changes in all driver files.
That's why this is an RFC.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f552d5f..59264f1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
+	unsigned int old_target_freq = target_freq;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
 
-	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-		target_freq, relation);
+	/* Make sure that target_freq is within supported range */
+	if (target_freq > policy->max)
+		target_freq = policy->max;
+	if (target_freq < policy->min)
+		target_freq = policy->min;
+
+	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+			policy->cpu, target_freq, relation, old_target_freq);
 	if (cpu_online(policy->cpu) && cpufreq_driver->target)
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 
-- 
1.7.12.rc2.18.g61b472e



WARNING: multiple messages have this Message-ID (diff)
From: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: rjw-KKrjLPT3xs0@public.gmane.org
Cc: linaro-dev-cunTk1MwBs8s++Sfvej+rw@public.gmane.org,
	patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
	Viresh Kumar
	<viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	cpufreq-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	pdsw-power-team-5wv7dgnIgG8@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: [RFC] cpufreq: Make sure target freq is within limits
Date: Thu, 25 Oct 2012 12:03:34 +0530	[thread overview]
Message-ID: <f0099171c1c4f3048d0f29b7deb42144f26ac5d5.1351146515.git.viresh.kumar@linaro.org> (raw)

Hi Rafael,

__cpufreq_driver_target() must not pass target frequency beyond the limits of
current policy.

Today most of cpufreq platform drivers are doing this check in their target
routines. Why not move it to __cpufreq_driver_target().

I wanted to get your opinion on this before making changes in all driver files.
That's why this is an RFC.

Signed-off-by: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/cpufreq/cpufreq.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f552d5f..59264f1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
+	unsigned int old_target_freq = target_freq;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
 
-	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-		target_freq, relation);
+	/* Make sure that target_freq is within supported range */
+	if (target_freq > policy->max)
+		target_freq = policy->max;
+	if (target_freq < policy->min)
+		target_freq = policy->min;
+
+	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+			policy->cpu, target_freq, relation, old_target_freq);
 	if (cpu_online(policy->cpu) && cpufreq_driver->target)
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 
-- 
1.7.12.rc2.18.g61b472e

WARNING: multiple messages have this Message-ID (diff)
From: viresh.kumar@linaro.org (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] cpufreq: Make sure target freq is within limits
Date: Thu, 25 Oct 2012 12:03:34 +0530	[thread overview]
Message-ID: <f0099171c1c4f3048d0f29b7deb42144f26ac5d5.1351146515.git.viresh.kumar@linaro.org> (raw)

Hi Rafael,

__cpufreq_driver_target() must not pass target frequency beyond the limits of
current policy.

Today most of cpufreq platform drivers are doing this check in their target
routines. Why not move it to __cpufreq_driver_target().

I wanted to get your opinion on this before making changes in all driver files.
That's why this is an RFC.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f552d5f..59264f1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
+	unsigned int old_target_freq = target_freq;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
 
-	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-		target_freq, relation);
+	/* Make sure that target_freq is within supported range */
+	if (target_freq > policy->max)
+		target_freq = policy->max;
+	if (target_freq < policy->min)
+		target_freq = policy->min;
+
+	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+			policy->cpu, target_freq, relation, old_target_freq);
 	if (cpu_online(policy->cpu) && cpufreq_driver->target)
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 
-- 
1.7.12.rc2.18.g61b472e

             reply	other threads:[~2012-10-25  6:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-25  6:33 Viresh Kumar [this message]
2012-10-25  6:33 ` [RFC] cpufreq: Make sure target freq is within limits Viresh Kumar
2012-10-25  6:33 ` Viresh Kumar
2012-10-26 11:23 ` Rafael J. Wysocki
2012-10-26 11:23   ` Rafael J. Wysocki

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