| Message ID | 20231220231753.1824364-8-lukasz.luba@arm.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | Add callback for cooling list update to speed-up IPA | expand |
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index d8ff74a4338a..299c0fb16593 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -936,7 +936,11 @@ ssize_t weight_store(struct device *dev, struct device_attribute *attr, return ret; instance = container_of(attr, struct thermal_instance, weight_attr); + + /* Don't race with governors using the 'weight' value */ + mutex_lock(&instance->tz->lock); instance->weight = weight; + mutex_unlock(&instance->tz->lock); return count; }
User space can change the weight of a thermal instance via sysfs while the .throttle() callback is running for a governor, because weight_store() does not use the zone lock. The IPA governor uses instance weight values for power calculations and caches the sum of them as total_weight, so it gets confused when one of them changes while its .throttle() callback is running. To prevent that from happening, use thermal zone locking in weight_store(). Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- drivers/thermal/thermal_sysfs.c | 4 ++++ 1 file changed, 4 insertions(+)