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Groups > linux.kernel > #1718759

[PATCH 08/12] PM / devfreq: Show the available min/max frequency through sysfs node

From Chanwoo Choi <cw00.choi@samsung.com>
Newsgroups linux.kernel
Subject [PATCH 08/12] PM / devfreq: Show the available min/max frequency through sysfs node
Date 2017-08-24 03:50 +0200
Message-ID <uhPrr-8ei-17@gated-at.bofh.it> (permalink)
References <uhPrr-8ei-3@gated-at.bofh.it> <uhPrr-8ei-19@gated-at.bofh.it> <uhPrr-8ei-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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The existing {min|max}_freq sysfs nodes don't consider whether min/max_freq
are available or not. Those sysfs nodes show just the stored value
in the struct devfreq.

The devfreq uses the OPP interface and then dev_pm_opp_{disable|add}()
might change the state of the device's supported frequency. This patch
shows the available minimum and maximum frequency through sysfs node.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index be3d42f140ff..8b0bbfa0a50b 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1148,7 +1148,14 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
-	return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
+	struct devfreq *df = to_devfreq(dev);
+	unsigned long min_freq = to_devfreq(dev)->min_freq;
+	unsigned long available_min_freq = find_available_min_freq(df);
+
+	if (available_min_freq != 0 && min_freq < available_min_freq)
+		min_freq = available_min_freq;
+
+	return sprintf(buf, "%lu\n", min_freq);
 }
 
 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
@@ -1186,7 +1193,14 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
-	return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
+	struct devfreq *df = to_devfreq(dev);
+	unsigned long max_freq = to_devfreq(dev)->max_freq;
+	unsigned long available_max_freq = find_available_max_freq(df);
+
+	if (available_max_freq != 0 && max_freq > available_max_freq)
+		max_freq = available_max_freq;
+
+	return sprintf(buf, "%lu\n", max_freq);
 }
 static DEVICE_ATTR_RW(max_freq);
 
-- 
1.9.1

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[PATCH 08/12] PM / devfreq: Show the available min/max frequency  through sysfs node Chanwoo Choi <cw00.choi@samsung.com> - 2017-08-24 03:50 +0200

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