diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 11 | ||||
| -rw-r--r-- | drivers/devfreq/devfreq.c | 29 |
2 files changed, 35 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 75897e2fde43..9758eb85ade3 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -55,12 +55,15 @@ What: /sys/class/devfreq/.../trans_stat Date: October 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Description: - This ABI shows the statistics of devfreq behavior on a - specific device. It shows the time spent in each state and - the number of transitions between states. + This ABI shows or clears the statistics of devfreq behavior + on a specific device. It shows the time spent in each state + and the number of transitions between states. In order to activate this ABI, the devfreq target device driver should provide the list of available frequencies - with its profile. + with its profile. If need to reset the statistics of devfreq + behavior on a specific device, enter 0(zero) to 'trans_stat' + as following: + echo 0 > /sys/class/devfreq/.../trans_stat What: /sys/class/devfreq/.../userspace/set_freq Date: September 2011 diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 554d155106a5..af5bd521a734 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1597,7 +1597,34 @@ static ssize_t trans_stat_show(struct device *dev, devfreq->total_trans); return len; } -static DEVICE_ATTR_RO(trans_stat); + +static ssize_t trans_stat_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct devfreq *df = to_devfreq(dev); + int err, value; + + if (df->profile->max_state == 0) + return count; + + err = kstrtoint(buf, 10, &value); + if (err || value != 0) + return -EINVAL; + + mutex_lock(&df->lock); + memset(df->time_in_state, 0, (df->profile->max_state * + sizeof(*df->time_in_state))); + memset(df->trans_table, 0, array3_size(sizeof(unsigned int), + df->profile->max_state, + df->profile->max_state)); + df->total_trans = 0; + df->last_stat_updated = get_jiffies_64(); + mutex_unlock(&df->lock); + + return count; +} +static DEVICE_ATTR_RW(trans_stat); static struct attribute *devfreq_attrs[] = { &dev_attr_name.attr, |