linux-kernel - [PATCH 2/3] PM / devfreq: Unify frequency change to devfreq_update

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Message-Id: <20201008075403.26181-3-cw00.choi@samsung.com>
Date:   Thu,  8 Oct 2020 16:54:02 +0900
From:   Chanwoo Choi <cw00.choi@...sung.com>
To:     linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     mka@...omium.org, rostedt@...dmis.org, mingo@...hat.com,
        cw00.choi@...sung.com, chanwoo@...nel.org,
        myungjoo.ham@...sung.com, kyungmin.park@...sung.com
Subject: [PATCH 2/3] PM / devfreq: Unify frequency change to
 devfreq_update_target func

The update_devfreq() and update_passive_devfreq() have the duplicate
code when changing the target frequency on final stage. So, unify
frequency change code to devfreq_update_target() to remove the
duplicate code and to centralize the frequency change code.

Signed-off-by: Chanwoo Choi <cw00.choi@...sung.com>
---
 drivers/devfreq/devfreq.c          | 29 ++++++++++++++++-----
 drivers/devfreq/governor.h         |  1 +
 drivers/devfreq/governor_passive.c | 42 +++++++-----------------------
 3 files changed, 33 insertions(+), 39 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 379aaaabf25d..5b069a8a1026 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -384,18 +384,19 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
 	return err;
 }
 
-/* Load monitoring helper functions for governors use */
-
 /**
- * update_devfreq() - Reevaluate the device and configure frequency.
+ * devfreq_update_target() - Reevaluate the device and configure frequency
+ *			   on the final stage.
  * @devfreq:	the devfreq instance.
+ * @freq:	the new frequency of parent device. This argument
+ *		is only used for devfreq device using passive governor.
  *
- * Note: Lock devfreq->lock before calling update_devfreq
- *	 This function is exported for governors.
+ * Note: Lock devfreq->lock before calling devfreq_update_target. This function
+ *	 should be only used by both update_devfreq() and devfreq governors.
  */
-int update_devfreq(struct devfreq *devfreq)
+int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
 {
-	unsigned long freq, min_freq, max_freq;
+	unsigned long min_freq, max_freq;
 	int err = 0;
 	u32 flags = 0;
 
@@ -420,7 +421,21 @@ int update_devfreq(struct devfreq *devfreq)
 	}
 
 	return devfreq_set_target(devfreq, freq, flags);
+}
+EXPORT_SYMBOL(devfreq_update_target);
+
+/* Load monitoring helper functions for governors use */
 
+/**
+ * update_devfreq() - Reevaluate the device and configure frequency.
+ * @devfreq:	the devfreq instance.
+ *
+ * Note: Lock devfreq->lock before calling update_devfreq
+ *	 This function is exported for governors.
+ */
+int update_devfreq(struct devfreq *devfreq)
+{
+	return devfreq_update_target(devfreq, 0L);
 }
 EXPORT_SYMBOL(update_devfreq);
 
diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
index eb6392d397b3..871150be4391 100644
--- a/drivers/devfreq/governor.h
+++ b/drivers/devfreq/governor.h
@@ -85,6 +85,7 @@ int devfreq_add_governor(struct devfreq_governor *governor);
 int devfreq_remove_governor(struct devfreq_governor *governor);
 
 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq);
+int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
 
 static inline int devfreq_update_stats(struct devfreq *df)
 {
diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 432a4cc683f7..8deb071d5d26 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -92,36 +92,6 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	return ret;
 }
 
-static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
-{
-	int ret;
-
-	if (!devfreq->governor)
-		return -EINVAL;
-
-	mutex_lock_nested(&devfreq->lock, SINGLE_DEPTH_NESTING);
-
-	ret = devfreq->governor->get_target_freq(devfreq, &freq);
-	if (ret < 0)
-		goto out;
-
-	ret = devfreq->profile->target(devfreq->dev.parent, &freq, 0);
-	if (ret < 0)
-		goto out;
-
-	if (devfreq->profile->freq_table
-		&& (devfreq_update_status(devfreq, freq)))
-		dev_err(&devfreq->dev,
-			"Couldn't update frequency transition information.\n");
-
-	devfreq->previous_freq = freq;
-
-out:
-	mutex_unlock(&devfreq->lock);
-
-	return 0;
-}
-
 static int devfreq_passive_notifier_call(struct notifier_block *nb,
 				unsigned long event, void *ptr)
 {
@@ -131,17 +101,25 @@ static int devfreq_passive_notifier_call(struct notifier_block *nb,
 	struct devfreq *parent = (struct devfreq *)data->parent;
 	struct devfreq_freqs *freqs = (struct devfreq_freqs *)ptr;
 	unsigned long freq = freqs->new;
+	int ret = 0;
 
+	mutex_lock_nested(&devfreq->lock, SINGLE_DEPTH_NESTING);
 	switch (event) {
 	case DEVFREQ_PRECHANGE:
 		if (parent->previous_freq > freq)
-			update_devfreq_passive(devfreq, freq);
+			ret = devfreq_update_target(devfreq, freq);
+
 		break;
 	case DEVFREQ_POSTCHANGE:
 		if (parent->previous_freq < freq)
-			update_devfreq_passive(devfreq, freq);
+			ret = devfreq_update_target(devfreq, freq);
 		break;
 	}
+	mutex_unlock(&devfreq->lock);
+
+	if (ret < 0)
+		dev_warn(&devfreq->dev,
+			"failed to update devfreq using passive governor\n");
 
 	return NOTIFY_DONE;
 }
-- 
2.17.1