@@ -132,14 +132,10 @@ static void devfreq_get_freq_range(struct devfreq *devfreq,
*min_freq = max(*min_freq, HZ_PER_KHZ * (unsigned long)dev_pm_qos_read_value(
devfreq->dev.parent, DEV_PM_QOS_MIN_FREQUENCY));
*max_freq = min(*max_freq, HZ_PER_KHZ * (unsigned long)dev_pm_qos_read_value(
devfreq->dev.parent, DEV_PM_QOS_MAX_FREQUENCY));
- /* constraints from sysfs: */
- *min_freq = max(*min_freq, devfreq->min_freq);
- *max_freq = min(*max_freq, devfreq->max_freq);
-
/* constraints from opp interface: */
*min_freq = max(*min_freq, devfreq->scaling_min_freq);
/* scaling_max_freq can be zero on error */
if (devfreq->scaling_max_freq)
*max_freq = min(*max_freq, devfreq->scaling_max_freq);
@@ -679,10 +675,12 @@ static void devfreq_dev_release(struct device *dev)
DEV_PM_QOS_MIN_FREQUENCY);
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
+ dev_pm_qos_remove_request(&devfreq->max_freq_req);
+ dev_pm_qos_remove_request(&devfreq->min_freq_req);
mutex_destroy(&devfreq->lock);
kfree(devfreq);
}
/**
@@ -744,18 +742,28 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq->scaling_min_freq = find_available_min_freq(devfreq);
if (!devfreq->scaling_min_freq) {
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) {
err = -EINVAL;
goto err_dev;
}
- devfreq->max_freq = devfreq->scaling_max_freq;
+
+ /* dev_pm_qos requests for min/max freq from sysfs */
+ err = dev_pm_qos_add_request(dev, &devfreq->min_freq_req,
+ DEV_PM_QOS_MIN_FREQUENCY, 0);
+ if (err < 0) {
+ goto err_dev;
+ }
+ err = dev_pm_qos_add_request(dev, &devfreq->max_freq_req,
+ DEV_PM_QOS_MAX_FREQUENCY, S32_MAX);
+ if (err < 0) {
+ goto err_dev;
+ }
devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
atomic_set(&devfreq->suspend_count, 0);
dev_set_name(&devfreq->dev, "devfreq%d",
@@ -836,12 +844,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
err_init:
mutex_unlock(&devfreq_list_lock);
err_devfreq:
devfreq_remove_device(devfreq);
- devfreq = NULL;
+ return ERR_PTR(err);
err_dev:
+ if (dev_pm_qos_request_active(&devfreq->max_freq_req))
+ dev_pm_qos_remove_request(&devfreq->max_freq_req);
+ if (dev_pm_qos_request_active(&devfreq->min_freq_req))
+ dev_pm_qos_remove_request(&devfreq->min_freq_req);
kfree(devfreq);
err_out:
return ERR_PTR(err);
}
EXPORT_SYMBOL(devfreq_add_device);
@@ -1400,14 +1412,17 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
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 dev_pm_qos */
+ if (value)
+ value = value / HZ_PER_KHZ;
+
+ ret = dev_pm_qos_update_request(&df->min_freq_req, value);
+ if (ret < 0)
+ return ret;
return count;
}
static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
@@ -1432,19 +1447,19 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
- mutex_lock(&df->lock);
-
- /* Interpret zero as "don't care" */
- if (!value)
- value = ULONG_MAX;
+ /* round up to kHz for dev_pm_qos and interpret zero as "don't care" */
+ if (value)
+ value = DIV_ROUND_UP(value, HZ_PER_KHZ);
+ else
+ value = S32_MAX;
- df->max_freq = value;
- update_devfreq(df);
- mutex_unlock(&df->lock);
+ ret = dev_pm_qos_update_request(&df->max_freq_req, value);
+ if (ret < 0)
+ return ret;
return count;
}
static DEVICE_ATTR_RW(min_freq);
@@ -11,10 +11,11 @@
#define __LINUX_DEVFREQ_H__
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pm_opp.h>
+#include <linux/pm_qos.h>
#define DEVFREQ_NAME_LEN 16
/* DEVFREQ governor name */
#define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand"
@@ -121,12 +122,12 @@ struct devfreq_dev_profile {
* devfreq.nb to the corresponding register notifier call chain.
* @work: delayed work for load monitoring.
* @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)
+ * @min_freq_req: Limit minimum frequency requested by user (0: none)
+ * @max_freq_req: Limit maximum frequency requested by user (0: none)
* @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.
* @suspend_freq: frequency of a device set during suspend phase.
* @resume_freq: frequency of a device set in resume phase.
@@ -161,12 +162,12 @@ struct devfreq {
unsigned long previous_freq;
struct devfreq_dev_status last_status;
void *data; /* private data for governors */
- unsigned long min_freq;
- unsigned long max_freq;
+ struct dev_pm_qos_request min_freq_req;
+ struct dev_pm_qos_request max_freq_req;
unsigned long scaling_min_freq;
unsigned long scaling_max_freq;
bool stop_polling;
unsigned long suspend_freq;
Switch the handling of min_freq and max_freq from sysfs to use the dev_pm_qos interface. Since dev_pm_qos handles frequencies as kHz this change reduces the precision of min_freq and max_freq. This shouldn't introduce problems because frequencies which are not an integer number of kHz are likely not an integer number of Hz either. Try to ensure compatibilitity by rounding min values down and rounding max values up. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> --- drivers/devfreq/devfreq.c | 53 +++++++++++++++++++++++++-------------- include/linux/devfreq.h | 9 ++++--- 2 files changed, 39 insertions(+), 23 deletions(-)