From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it. However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.
Moreover, input processing need not be done under the thermal zone lock
in any of these functions.
Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.
While at it, make trip_point_hyst_store() reject negative hysteresis
values.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
v3 -> v4: Don't check trip_id against boundaries in trip_point_temp_store() and
trip_point_hyst_store() (Daniel).
v2 -> v3: No changes
v1 -> v2: Still check device_is_registered() under the zone lock
---
drivers/thermal/thermal_core.h | 2 +
drivers/thermal/thermal_sysfs.c | 52 +++++++++++++++++++++++++++-------------
drivers/thermal/thermal_trip.c | 45 ++++++----------------------------
include/linux/thermal.h | 4 ---
4 files changed, 47 insertions(+), 56 deletions(-)
On 05/12/2023 13:24, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Both trip_point_temp_store() and trip_point_hyst_store() use
> thermal_zone_set_trip() to update a given trip point, but none of them
> actually needs to change more than one field in struct thermal_trip
> representing it. However, each of them effectively calls
> __thermal_zone_get_trip() twice in a row for the same trip index value,
> once directly and once via thermal_zone_set_trip(), which is not
> particularly efficient, and the way in which thermal_zone_set_trip()
> carries out the update is not particularly straightforward.
>
> Moreover, input processing need not be done under the thermal zone lock
> in any of these functions.
>
> Rework trip_point_temp_store() and trip_point_hyst_store() to address
> the above, move the part of thermal_zone_set_trip() that is still
> useful to a new function called thermal_zone_trip_updated() and drop
> the rest of it.
>
> While at it, make trip_point_hyst_store() reject negative hysteresis
> values.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
===================================================================
@@ -120,8 +120,13 @@ trip_point_temp_store(struct device *dev
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
- struct thermal_trip trip;
+ struct thermal_trip *trip;
int trip_id, ret;
+ int temp;
+
+ ret = kstrtoint(buf, 10, &temp);
+ if (ret)
+ return -EINVAL;
if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
return -EINVAL;
@@ -133,15 +138,20 @@ trip_point_temp_store(struct device *dev
goto unlock;
}
- ret = __thermal_zone_get_trip(tz, trip_id, &trip);
- if (ret)
- goto unlock;
+ trip = &tz->trips[trip_id];
- ret = kstrtoint(buf, 10, &trip.temperature);
- if (ret)
- goto unlock;
+ if (temp != trip->temperature) {
+ if (tz->ops->set_trip_temp) {
+ ret = tz->ops->set_trip_temp(tz, trip_id, temp);
+ if (ret)
+ goto unlock;
+ }
+
+ trip->temperature = temp;
+
+ thermal_zone_trip_updated(tz, trip);
+ }
- ret = thermal_zone_set_trip(tz, trip_id, &trip);
unlock:
mutex_unlock(&tz->lock);
@@ -179,8 +189,13 @@ trip_point_hyst_store(struct device *dev
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
- struct thermal_trip trip;
+ struct thermal_trip *trip;
int trip_id, ret;
+ int hyst;
+
+ ret = kstrtoint(buf, 10, &hyst);
+ if (ret || hyst < 0)
+ return -EINVAL;
if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
return -EINVAL;
@@ -192,15 +207,20 @@ trip_point_hyst_store(struct device *dev
goto unlock;
}
- ret = __thermal_zone_get_trip(tz, trip_id, &trip);
- if (ret)
- goto unlock;
+ trip = &tz->trips[trip_id];
- ret = kstrtoint(buf, 10, &trip.hysteresis);
- if (ret)
- goto unlock;
+ if (hyst != trip->hysteresis) {
+ if (tz->ops->set_trip_hyst) {
+ ret = tz->ops->set_trip_hyst(tz, trip_id, hyst);
+ if (ret)
+ goto unlock;
+ }
+
+ trip->hysteresis = hyst;
+
+ thermal_zone_trip_updated(tz, trip);
+ }
- ret = thermal_zone_set_trip(tz, trip_id, &trip);
unlock:
mutex_unlock(&tz->lock);
===================================================================
@@ -124,6 +124,8 @@ int __thermal_zone_get_trip(struct therm
struct thermal_trip *trip);
int thermal_zone_trip_id(struct thermal_zone_device *tz,
const struct thermal_trip *trip);
+void thermal_zone_trip_updated(struct thermal_zone_device *tz,
+ const struct thermal_trip *trip);
int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp);
/* sysfs I/F */
===================================================================
@@ -147,42 +147,6 @@ int thermal_zone_get_trip(struct thermal
}
EXPORT_SYMBOL_GPL(thermal_zone_get_trip);
-int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
- const struct thermal_trip *trip)
-{
- struct thermal_trip t;
- int ret;
-
- ret = __thermal_zone_get_trip(tz, trip_id, &t);
- if (ret)
- return ret;
-
- if (t.type != trip->type)
- return -EINVAL;
-
- if (t.temperature != trip->temperature && tz->ops->set_trip_temp) {
- ret = tz->ops->set_trip_temp(tz, trip_id, trip->temperature);
- if (ret)
- return ret;
- }
-
- if (t.hysteresis != trip->hysteresis && tz->ops->set_trip_hyst) {
- ret = tz->ops->set_trip_hyst(tz, trip_id, trip->hysteresis);
- if (ret)
- return ret;
- }
-
- if (tz->trips && (t.temperature != trip->temperature || t.hysteresis != trip->hysteresis))
- tz->trips[trip_id] = *trip;
-
- thermal_notify_tz_trip_change(tz->id, trip_id, trip->type,
- trip->temperature, trip->hysteresis);
-
- __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
-
- return 0;
-}
-
int thermal_zone_trip_id(struct thermal_zone_device *tz,
const struct thermal_trip *trip)
{
@@ -192,3 +156,12 @@ int thermal_zone_trip_id(struct thermal_
*/
return trip - tz->trips;
}
+
+void thermal_zone_trip_updated(struct thermal_zone_device *tz,
+ const struct thermal_trip *trip)
+{
+ thermal_notify_tz_trip_change(tz->id, thermal_zone_trip_id(tz, trip),
+ trip->type, trip->temperature,
+ trip->hysteresis);
+ __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
+}
===================================================================
@@ -282,10 +282,6 @@ int __thermal_zone_get_trip(struct therm
struct thermal_trip *trip);
int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
struct thermal_trip *trip);
-
-int thermal_zone_set_trip(struct thermal_zone_device *tz, int trip_id,
- const struct thermal_trip *trip);
-
int for_each_thermal_trip(struct thermal_zone_device *tz,
int (*cb)(struct thermal_trip *, void *),
void *data);