Messages in this thread Patch in this message | | | From | Lukasz Luba <> | Subject | [PATCH v3 3/3] thermal: create a helper __thermal_cdev_update() without a lock | Date | Wed, 21 Apr 2021 18:41:45 +0100 |
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There is a need to have a helper function which updates cooling device state from the governors code. With this change governor can use lock and unlock while calling helper function. This avoid unnecessary second time lock/unlock which was in previous solution present in governor implementation. This new helper function must be called with mutex 'cdev->lock' hold.
The changed been discussed and part of code presented in thread: https://lore.kernel.org/linux-pm/20210419084536.25000-1-lukasz.luba@arm.com/
Co-developed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- drivers/thermal/gov_power_allocator.c | 5 +---- drivers/thermal/thermal_core.h | 1 + drivers/thermal/thermal_helpers.c | 28 +++++++++++++++++---------- 3 files changed, 20 insertions(+), 14 deletions(-)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index f379f1aaa3b5..a6cdb2e892da 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -595,12 +595,9 @@ static void allow_maximum_power(struct thermal_zone_device *tz, bool update) cdev->ops->get_requested_power(cdev, &req_power); if (update) - instance->cdev->updated = false; + __thermal_cdev_update(instance->cdev); mutex_unlock(&instance->cdev->lock); - - if (update) - thermal_cdev_update(instance->cdev); } mutex_unlock(&tz->lock); } diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h index 86b8cef7310e..726e327b4205 100644 --- a/drivers/thermal/thermal_core.h +++ b/drivers/thermal/thermal_core.h @@ -66,6 +66,7 @@ static inline bool cdev_is_power_actor(struct thermal_cooling_device *cdev) } void thermal_cdev_update(struct thermal_cooling_device *); +void __thermal_cdev_update(struct thermal_cooling_device *cdev); /** * struct thermal_trip - representation of a point in temperature domain diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c index 7f50f412e02a..3d7fd46104de 100644 --- a/drivers/thermal/thermal_helpers.c +++ b/drivers/thermal/thermal_helpers.c @@ -192,18 +192,12 @@ static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, thermal_cooling_device_stats_update(cdev, target); } -void thermal_cdev_update(struct thermal_cooling_device *cdev) + +void __thermal_cdev_update(struct thermal_cooling_device *cdev) { struct thermal_instance *instance; unsigned long target = 0; - mutex_lock(&cdev->lock); - /* cooling device is updated*/ - if (cdev->updated) { - mutex_unlock(&cdev->lock); - return; - } - /* Make sure cdev enters the deepest cooling state */ list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { dev_dbg(&cdev->device, "zone%d->target=%lu\n", @@ -216,11 +210,25 @@ void thermal_cdev_update(struct thermal_cooling_device *cdev) thermal_cdev_set_cur_state(cdev, target); - cdev->updated = true; - mutex_unlock(&cdev->lock); trace_cdev_update(cdev, target); dev_dbg(&cdev->device, "set to state %lu\n", target); } + +/** + * thermal_cdev_update - update cooling device state if needed + * @cdev: pointer to struct thermal_cooling_device + * + * Update the cooling device state if there is a need. + */ +void thermal_cdev_update(struct thermal_cooling_device *cdev) +{ + mutex_lock(&cdev->lock); + if (!cdev->updated) { + __thermal_cdev_update(cdev); + cdev->updated = true; + } + mutex_unlock(&cdev->lock); +} EXPORT_SYMBOL(thermal_cdev_update); /** -- 2.17.1
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