devfreq_simple_ondemand_data only needs to be initialized once when
calling devm_devfreq_add_device. It's unnecessary to put the data
check logic in the hot path (.get_target_freq()) where it will be
called all the time during polling. Instead, we only check and initialize
it one time during DEVFREQ_GOV_START.
This also helps check data validability in advance during DEVFREQ_GOV_START
rather than checking it later when running .get_target_freq().
Signed-off-by: Dong Aisheng <aisheng.d...@nxp.com>
---
drivers/devfreq/governor_simpleondemand.c | 50 +++++++++++++++--------
1 file changed, 34 insertions(+), 16 deletions(-)
diff --git a/drivers/devfreq/governor_simpleondemand.c
b/drivers/devfreq/governor_simpleondemand.c
index ea287b57cbf3..341eb7e9dc04 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -15,15 +15,19 @@
/* Default constants for DevFreq-Simple-Ondemand (DFSO) */
#define DFSO_UPTHRESHOLD (90)
#define DFSO_DOWNDIFFERENCTIAL (5)
+
+static struct devfreq_simple_ondemand_data od_default = {
+ .upthreshold = DFSO_UPTHRESHOLD,
+ .downdifferential = DFSO_DOWNDIFFERENCTIAL,
+};
+
static int devfreq_simple_ondemand_func(struct devfreq *df,
unsigned long *freq)
{
int err;
struct devfreq_dev_status *stat;
unsigned long long a, b;
- unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
- unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
- struct devfreq_simple_ondemand_data *data = df->data;
+ struct devfreq_simple_ondemand_data *od = df->data;
err = devfreq_update_stats(df);
if (err)
@@ -31,16 +35,6 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
stat = &df->last_status;
- if (data) {
- if (data->upthreshold)
- dfso_upthreshold = data->upthreshold;
- if (data->downdifferential)
- dfso_downdifferential = data->downdifferential;
- }
- if (dfso_upthreshold > 100 ||
- dfso_upthreshold < dfso_downdifferential)
- return -EINVAL;
-
/* Assume MAX if it is going to be divided by zero */
if (stat->total_time == 0) {
*freq = DEVFREQ_MAX_FREQ;
@@ -55,7 +49,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
/* Set MAX if it's busy enough */
if (stat->busy_time * 100 >
- stat->total_time * dfso_upthreshold) {
+ stat->total_time * od->upthreshold) {
*freq = DEVFREQ_MAX_FREQ;
return 0;
}
@@ -68,7 +62,7 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
/* Keep the current frequency */
if (stat->busy_time * 100 >
- stat->total_time * (dfso_upthreshold - dfso_downdifferential)) {
+ stat->total_time * (od->upthreshold - od->downdifferential)) {
*freq = stat->current_frequency;
return 0;
}
@@ -78,17 +72,41 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
a *= stat->current_frequency;
b = div_u64(a, stat->total_time);
b *= 100;
- b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
+ b = div_u64(b, (od->upthreshold - od->downdifferential / 2));
*freq = (unsigned long) b;
return 0;
}
+static int devfreq_simple_ondemand_check_od(struct devfreq *devfreq)
+{
+ struct devfreq_simple_ondemand_data *od = devfreq->data;
+
+ if (od) {
+ if (!od->upthreshold)
+ od->upthreshold = DFSO_UPTHRESHOLD;
+
+ if (!od->downdifferential)
+ od->downdifferential = DFSO_DOWNDIFFERENCTIAL;
+
+ if (od->upthreshold > 100 ||
+ od->upthreshold < od->downdifferential)
+ return -EINVAL;
+ } else {
+ od = &od_default;
+ }
+
+ return 0;
+}
+
static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
unsigned int event, void *data)
{
switch (event) {
case DEVFREQ_GOV_START:
+ if (devfreq_simple_ondemand_check_od(devfreq))
+ return -EINVAL;
+
return devfreq_monitor_start(devfreq);
case DEVFREQ_GOV_STOP:
--
2.25.1
