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From: Dong Aisheng <aisheng.dong@nxp.com>
To: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: dongas86@gmail.com, kernel@pengutronix.de, shawnguo@kernel.org,
	linux-imx@nxp.com, linux-kernel@vger.kernel.org,
	myungjoo.ham@samsung.com, kyungmin.park@samsung.com,
	cw00.choi@samsung.com, abel.vesa@nxp.com,
	Dong Aisheng <aisheng.dong@nxp.com>
Subject: [PATCH V2 RESEND 3/4] PM / devfreq: bail out early if no freq changes in devfreq_set_target
Date: Tue, 23 Mar 2021 15:20:10 +0800	[thread overview]
Message-ID: <1616484011-26702-4-git-send-email-aisheng.dong@nxp.com> (raw)
In-Reply-To: <1616484011-26702-1-git-send-email-aisheng.dong@nxp.com>

It's unnecessary to set the same freq again and run notifier calls.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
 drivers/devfreq/devfreq.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 85927bd7ee76..a6ee91dd17bd 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -352,13 +352,16 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 {
 	struct devfreq_freqs freqs;
 	unsigned long cur_freq;
-	int err = 0;
+	int err;
 
 	if (devfreq->profile->get_cur_freq)
 		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
 	else
 		cur_freq = devfreq->previous_freq;
 
+	if (new_freq == cur_freq)
+		return 0;
+
 	freqs.old = cur_freq;
 	freqs.new = new_freq;
 	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
@@ -375,7 +378,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
 	 * change order of between devfreq device and passive devfreq device.
 	 */
-	if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
+	if (trace_devfreq_frequency_enabled())
 		trace_devfreq_frequency(devfreq, new_freq, cur_freq);
 
 	freqs.new = new_freq;
@@ -390,7 +393,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	if (devfreq->suspend_freq)
 		devfreq->resume_freq = new_freq;
 
-	return err;
+	return 0;
 }
 
 /**
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Dong Aisheng <aisheng.dong@nxp.com>
To: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: dongas86@gmail.com, kernel@pengutronix.de, shawnguo@kernel.org,
	linux-imx@nxp.com, linux-kernel@vger.kernel.org,
	myungjoo.ham@samsung.com, kyungmin.park@samsung.com,
	cw00.choi@samsung.com, abel.vesa@nxp.com,
	Dong Aisheng <aisheng.dong@nxp.com>
Subject: [PATCH V2 RESEND 3/4] PM / devfreq: bail out early if no freq changes in devfreq_set_target
Date: Tue, 23 Mar 2021 15:20:10 +0800	[thread overview]
Message-ID: <1616484011-26702-4-git-send-email-aisheng.dong@nxp.com> (raw)
In-Reply-To: <1616484011-26702-1-git-send-email-aisheng.dong@nxp.com>

It's unnecessary to set the same freq again and run notifier calls.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
 drivers/devfreq/devfreq.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 85927bd7ee76..a6ee91dd17bd 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -352,13 +352,16 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 {
 	struct devfreq_freqs freqs;
 	unsigned long cur_freq;
-	int err = 0;
+	int err;
 
 	if (devfreq->profile->get_cur_freq)
 		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
 	else
 		cur_freq = devfreq->previous_freq;
 
+	if (new_freq == cur_freq)
+		return 0;
+
 	freqs.old = cur_freq;
 	freqs.new = new_freq;
 	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
@@ -375,7 +378,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
 	 * change order of between devfreq device and passive devfreq device.
 	 */
-	if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
+	if (trace_devfreq_frequency_enabled())
 		trace_devfreq_frequency(devfreq, new_freq, cur_freq);
 
 	freqs.new = new_freq;
@@ -390,7 +393,7 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	if (devfreq->suspend_freq)
 		devfreq->resume_freq = new_freq;
 
-	return err;
+	return 0;
 }
 
 /**
-- 
2.25.1


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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-03-23  7:35 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-23  7:20 [PATCH V2 RESEND 0/4] PM / devfreq: a few small fixes and improvements Dong Aisheng
2021-03-23  7:20 ` Dong Aisheng
2021-03-23  7:20 ` [PATCH V2 RESEND 1/4] PM / devfreq: Use more accurate returned new_freq as resume_freq Dong Aisheng
2021-03-23  7:20   ` Dong Aisheng
2021-03-23 14:55   ` Chanwoo Choi
2021-03-23 14:55     ` Chanwoo Choi
2021-03-23  7:20 ` [PATCH V2 RESEND 2/4] PM / devfreq: Remove the invalid description for get_target_freq Dong Aisheng
2021-03-23  7:20   ` Dong Aisheng
2021-03-23 14:56   ` Chanwoo Choi
2021-03-23 14:56     ` Chanwoo Choi
2021-03-23  7:20 ` Dong Aisheng [this message]
2021-03-23  7:20   ` [PATCH V2 RESEND 3/4] PM / devfreq: bail out early if no freq changes in devfreq_set_target Dong Aisheng
2021-03-23 15:01   ` Chanwoo Choi
2021-03-23 15:01     ` Chanwoo Choi
2021-05-19  6:51     ` Dong Aisheng
2021-05-19  6:51       ` Dong Aisheng
2021-03-23  7:20 ` [PATCH V2 RESEND 4/4] PM / devfreq: imx8m-ddrc: remove imx8m_ddrc_get_dev_status Dong Aisheng
2021-03-23  7:20   ` Dong Aisheng
2021-03-23 14:56   ` Chanwoo Choi
2021-03-23 14:56     ` Chanwoo Choi

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