diff options
| author | Zhang Rui <rui.zhang@intel.com> | 2012-07-24 10:56:21 +0200 |
|---|---|---|
| committer | Zhang Rui <rui.zhang@intel.com> | 2012-09-24 08:44:37 +0200 |
| commit | f4a821ce6ed41970d0155f55067fb07009974fbe (patch) | |
| tree | 6cceeaa90060fb17985fbe7f9b5aa9466cf03d8d | |
| parent | Thermal: Unify the code for both active and passive cooling (diff) | |
| download | linux-f4a821ce6ed41970d0155f55067fb07009974fbe.tar.xz linux-f4a821ce6ed41970d0155f55067fb07009974fbe.zip | |
Thermal: Introduce locking for cdev.thermal_instances list.
we need to go over all the thermal_instance list of a cooling device
to decide which cooling state to put the cooling device to.
But at this time, as a cooling device may be referenced in multiple
thermal zones, we need to lock the list first in case
another thermal zone is updating this cooling device.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Eduardo Valentin <eduardo.valentin@ti.com>
| -rw-r--r-- | drivers/thermal/thermal_sys.c | 8 | ||||
| -rw-r--r-- | include/linux/thermal.h | 1 |
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c index 6e9d3dc9d89b..5be8728c88a3 100644 --- a/drivers/thermal/thermal_sys.c +++ b/drivers/thermal/thermal_sys.c @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, goto remove_symbol_link; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry(pos, &tz->thermal_instances, tz_node) if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { result = -EEXIST; @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, list_add_tail(&dev->tz_node, &tz->thermal_instances); list_add_tail(&dev->cdev_node, &cdev->thermal_instances); } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); if (!result) @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, struct thermal_instance *pos, *next; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { list_del(&pos->tz_node); list_del(&pos->cdev_node); + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); goto unbind; } } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); return -ENODEV; @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, } strcpy(cdev->type, type); + mutex_init(&cdev->lock); INIT_LIST_HEAD(&cdev->thermal_instances); cdev->ops = ops; cdev->updated = true; @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (cdev->updated) return; + mutex_lock(&cdev->lock); /* Make sure cdev enters the deepest cooling state */ list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { if (instance->target == THERMAL_NO_TARGET) @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (instance->target > target) target = instance->target; } + mutex_unlock(&cdev->lock); cdev->ops->set_cur_state(cdev, target); cdev->updated = true; } diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 76d0fe88eb1c..91b34812cd84 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -95,6 +95,7 @@ struct thermal_cooling_device { void *devdata; const struct thermal_cooling_device_ops *ops; bool updated; /* true if the cooling device does not need update */ + struct mutex lock; /* protect thermal_instances list */ struct list_head thermal_instances; struct list_head node; }; |