diff options
| author | Lukasz Luba <lukasz.luba@arm.com> | 2023-12-20 23:17:51 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-12-29 18:01:00 +0100 |
| commit | 879c9dc511732b74a04f11336e00f12783337a8a (patch) | |
| tree | 8d9d143d92e7ba3ff2bc5c97e54ff938172a7578 /drivers/thermal | |
| parent | e3ecd5716b957ff0e558e853d34be8d1e8173f64 (diff) | |
| download | linux-879c9dc511732b74a04f11336e00f12783337a8a.tar.gz | |
thermal/sysfs: Update instance->weight under tz lock
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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/thermal')
| -rw-r--r-- | drivers/thermal/thermal_sysfs.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index d8ff74a4338a4f..299c0fb1659306 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; } |