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path: root/drivers/devfreq/devfreq.c
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Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c83
1 files changed, 62 insertions, 21 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 42c1eed44..93df6cef4 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -438,10 +438,14 @@ static void devfreq_monitor(struct work_struct *work)
if (err)
dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
+ if (devfreq->stop_polling)
+ goto out;
+
queue_delayed_work(devfreq_wq, &devfreq->work,
msecs_to_jiffies(devfreq->profile->polling_ms));
- mutex_unlock(&devfreq->lock);
+out:
+ mutex_unlock(&devfreq->lock);
trace_devfreq_monitor(devfreq);
}
@@ -459,6 +463,10 @@ void devfreq_monitor_start(struct devfreq *devfreq)
if (devfreq->governor->interrupt_driven)
return;
+ mutex_lock(&devfreq->lock);
+ if (delayed_work_pending(&devfreq->work))
+ goto out;
+
switch (devfreq->profile->timer) {
case DEVFREQ_TIMER_DEFERRABLE:
INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
@@ -467,12 +475,16 @@ void devfreq_monitor_start(struct devfreq *devfreq)
INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
break;
default:
- return;
+ goto out;
}
if (devfreq->profile->polling_ms)
queue_delayed_work(devfreq_wq, &devfreq->work,
msecs_to_jiffies(devfreq->profile->polling_ms));
+
+out:
+ devfreq->stop_polling = false;
+ mutex_unlock(&devfreq->lock);
}
EXPORT_SYMBOL(devfreq_monitor_start);
@@ -489,6 +501,14 @@ void devfreq_monitor_stop(struct devfreq *devfreq)
if (devfreq->governor->interrupt_driven)
return;
+ mutex_lock(&devfreq->lock);
+ if (devfreq->stop_polling) {
+ mutex_unlock(&devfreq->lock);
+ return;
+ }
+
+ devfreq->stop_polling = true;
+ mutex_unlock(&devfreq->lock);
cancel_delayed_work_sync(&devfreq->work);
}
EXPORT_SYMBOL(devfreq_monitor_stop);
@@ -1619,7 +1639,7 @@ static ssize_t trans_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
- ssize_t len;
+ ssize_t len = 0;
int i, j;
unsigned int max_state;
@@ -1628,7 +1648,7 @@ static ssize_t trans_stat_show(struct device *dev,
max_state = df->profile->max_state;
if (max_state == 0)
- return sprintf(buf, "Not Supported.\n");
+ return scnprintf(buf, PAGE_SIZE, "Not Supported.\n");
mutex_lock(&df->lock);
if (!df->stop_polling &&
@@ -1638,33 +1658,54 @@ static ssize_t trans_stat_show(struct device *dev,
}
mutex_unlock(&df->lock);
- len = sprintf(buf, " From : To\n");
- len += sprintf(buf + len, " :");
- for (i = 0; i < max_state; i++)
- len += sprintf(buf + len, "%10lu",
- df->profile->freq_table[i]);
+ len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n");
+ len += scnprintf(buf + len, PAGE_SIZE - len, " :");
+ for (i = 0; i < max_state; i++) {
+ if (len >= PAGE_SIZE - 1)
+ break;
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu",
+ df->profile->freq_table[i]);
+ }
+ if (len >= PAGE_SIZE - 1)
+ return PAGE_SIZE - 1;
- len += sprintf(buf + len, " time(ms)\n");
+ len += scnprintf(buf + len, PAGE_SIZE - len, " time(ms)\n");
for (i = 0; i < max_state; i++) {
+ if (len >= PAGE_SIZE - 1)
+ break;
if (df->profile->freq_table[i]
== df->previous_freq) {
- len += sprintf(buf + len, "*");
+ len += scnprintf(buf + len, PAGE_SIZE - len, "*");
} else {
- len += sprintf(buf + len, " ");
+ len += scnprintf(buf + len, PAGE_SIZE - len, " ");
+ }
+ if (len >= PAGE_SIZE - 1)
+ break;
+
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu:",
+ df->profile->freq_table[i]);
+ for (j = 0; j < max_state; j++) {
+ if (len >= PAGE_SIZE - 1)
+ break;
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%10u",
+ df->stats.trans_table[(i * max_state) + j]);
}
- len += sprintf(buf + len, "%10lu:",
- df->profile->freq_table[i]);
- for (j = 0; j < max_state; j++)
- len += sprintf(buf + len, "%10u",
- df->stats.trans_table[(i * max_state) + j]);
+ if (len >= PAGE_SIZE - 1)
+ break;
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%10llu\n", (u64)
+ jiffies64_to_msecs(df->stats.time_in_state[i]));
+ }
+
+ if (len < PAGE_SIZE - 1)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "Total transition : %u\n",
+ df->stats.total_trans);
- len += sprintf(buf + len, "%10llu\n", (u64)
- jiffies64_to_msecs(df->stats.time_in_state[i]));
+ if (len >= PAGE_SIZE - 1) {
+ pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n");
+ return -EFBIG;
}
- len += sprintf(buf + len, "Total transition : %u\n",
- df->stats.total_trans);
return len;
}