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-rw-r--r--drivers/devfreq/devfreq.c76
-rw-r--r--include/linux/devfreq.h9
2 files changed, 64 insertions, 21 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index f6e272085448..57f6944d65a6 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -141,10 +141,6 @@ static void get_freq_range(struct devfreq *devfreq,
*max_freq = min(*max_freq,
(unsigned long)HZ_PER_KHZ * qos_max_freq);
- /* Apply constraints from sysfs */
- *min_freq = max(*min_freq, devfreq->min_freq);
- *max_freq = min(*max_freq, devfreq->max_freq);
-
/* Apply constraints from OPP interface */
*min_freq = max(*min_freq, devfreq->scaling_min_freq);
*max_freq = min(*max_freq, devfreq->scaling_max_freq);
@@ -705,6 +701,19 @@ static void devfreq_dev_release(struct device *dev)
dev_warn(dev->parent,
"Failed to remove min_freq notifier: %d\n", err);
+ if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
+ err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
+ if (err)
+ dev_warn(dev->parent,
+ "Failed to remove max_freq request: %d\n", err);
+ }
+ if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
+ err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
+ if (err)
+ dev_warn(dev->parent,
+ "Failed to remove min_freq request: %d\n", err);
+ }
+
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
@@ -778,7 +787,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
err = -EINVAL;
goto err_dev;
}
- devfreq->min_freq = devfreq->scaling_min_freq;
devfreq->scaling_max_freq = find_available_max_freq(devfreq);
if (!devfreq->scaling_max_freq) {
@@ -786,7 +794,6 @@ struct devfreq *devfreq_add_device(struct device *dev,
err = -EINVAL;
goto err_dev;
}
- devfreq->max_freq = devfreq->scaling_max_freq;
devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
atomic_set(&devfreq->suspend_count, 0);
@@ -827,6 +834,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_unlock(&devfreq->lock);
+ err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
+ DEV_PM_QOS_MIN_FREQUENCY, 0);
+ if (err < 0)
+ goto err_devfreq;
+ err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
+ DEV_PM_QOS_MAX_FREQUENCY,
+ PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
+ if (err < 0)
+ goto err_devfreq;
+
devfreq->nb_min.notifier_call = qos_min_notifier_call;
err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min,
DEV_PM_QOS_MIN_FREQUENCY);
@@ -1412,14 +1429,22 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
unsigned long value;
int ret;
+ /*
+ * Protect against theoretical sysfs writes between
+ * device_add and dev_pm_qos_add_request
+ */
+ if (!dev_pm_qos_request_active(&df->user_min_freq_req))
+ return -EAGAIN;
+
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
- mutex_lock(&df->lock);
- df->min_freq = value;
- update_devfreq(df);
- mutex_unlock(&df->lock);
+ /* Round down to kHz for PM QoS */
+ ret = dev_pm_qos_update_request(&df->user_min_freq_req,
+ value / HZ_PER_KHZ);
+ if (ret < 0)
+ return ret;
return count;
}
@@ -1444,18 +1469,35 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
unsigned long value;
int ret;
+ /*
+ * Protect against theoretical sysfs writes between
+ * device_add and dev_pm_qos_add_request
+ */
+ if (!dev_pm_qos_request_active(&df->user_max_freq_req))
+ return -EINVAL;
+
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
- mutex_lock(&df->lock);
-
- if (!value)
- value = ULONG_MAX;
+ /*
+ * PM QoS frequencies are in kHz so we need to convert. Convert by
+ * rounding upwards so that the acceptable interval never shrinks.
+ *
+ * For example if the user writes "666666666" to sysfs this value will
+ * be converted to 666667 kHz and back to 666667000 Hz before an OPP
+ * lookup, this ensures that an OPP of 666666666Hz is still accepted.
+ *
+ * A value of zero means "no limit".
+ */
+ if (value)
+ value = DIV_ROUND_UP(value, HZ_PER_KHZ);
+ else
+ value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
- df->max_freq = value;
- update_devfreq(df);
- mutex_unlock(&df->lock);
+ ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
+ if (ret < 0)
+ return ret;
return count;
}
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 8b92ccbd1962..fb376b5b7281 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -13,6 +13,7 @@
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pm_opp.h>
+#include <linux/pm_qos.h>
#define DEVFREQ_NAME_LEN 16
@@ -123,8 +124,8 @@ struct devfreq_dev_profile {
* @previous_freq: previously configured frequency value.
* @data: Private data of the governor. The devfreq framework does not
* touch this.
- * @min_freq: Limit minimum frequency requested by user (0: none)
- * @max_freq: Limit maximum frequency requested by user (0: none)
+ * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs)
+ * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs)
* @scaling_min_freq: Limit minimum frequency requested by OPP interface
* @scaling_max_freq: Limit maximum frequency requested by OPP interface
* @stop_polling: devfreq polling status of a device.
@@ -163,8 +164,8 @@ struct devfreq {
void *data; /* private data for governors */
- unsigned long min_freq;
- unsigned long max_freq;
+ struct dev_pm_qos_request user_min_freq_req;
+ struct dev_pm_qos_request user_max_freq_req;
unsigned long scaling_min_freq;
unsigned long scaling_max_freq;
bool stop_polling;