thermal: sysfs: Rework the handling of trip point updates

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>

diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 0a3b3ec5120ba74018a28a2da8985d7f831112c8..7dfe6c8deb8ecb602e6dca9fab8f200a6ae23687 100644 (file)
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -124,6 +124,8 @@ int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
                            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 */

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index eef40d4f3063940616e5c1d1ba4c9872b9d5db7b..06202aa50060a3cbf91a579dadb10a83f0ddd3a8 100644 (file)
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -120,8 +120,13 @@ trip_point_temp_store(struct device *dev, struct device_attribute *attr,
                      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, struct device_attribute *attr,
                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, struct device_attribute *attr,
                      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, struct device_attribute *attr,
                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);
 

diff --git a/drivers/thermal/thermal_trip.c b/drivers/thermal/thermal_trip.c
index e3dd583234ddecb390c55aadab956b73d12624d9..90861dec7eb0fdbdf0d186f19cdc4b1e45d890a7 100644 (file)
--- a/drivers/thermal/thermal_trip.c
+++ b/drivers/thermal/thermal_trip.c
@@ -147,42 +147,6 @@ int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 }
 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_zone_device *tz,
         */
        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);
+}

diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 1f9ee869f9f9cd2e70f5e0f6471278bd25d327ce..0ea99f50d57c5b0565ed6c31b10b9dccd917c22b 100644 (file)
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -282,10 +282,6 @@ int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
                            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);