@@ -295,25 +295,16 @@ static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
cancel_delayed_work(&tz->poll_queue);
}
-static inline bool should_stop_polling(struct thermal_zone_device *tz)
-{
- return !thermal_zone_device_is_enabled(tz);
-}
-
static void monitor_thermal_zone(struct thermal_zone_device *tz)
{
- bool stop;
-
- stop = should_stop_polling(tz);
-
mutex_lock(&tz->lock);
- if (!stop && tz->passive)
+ if (tz->mode != THERMAL_DEVICE_ENABLED)
+ thermal_zone_device_set_polling(tz, 0);
+ else if (tz->passive)
thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
- else if (!stop && tz->polling_delay_jiffies)
+ else if (tz->polling_delay_jiffies)
thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
- else
- thermal_zone_device_set_polling(tz, 0);
mutex_unlock(&tz->lock);
}
@@ -480,7 +471,7 @@ void thermal_zone_device_update(struct thermal_zone_device *tz,
{
int count;
- if (should_stop_polling(tz))
+ if (!thermal_zone_device_is_enabled(tz))
return;
if (atomic_read(&in_suspend))
The following commit has been merged into the thermal/next branch of thermal: Commit-ID: 15a73839e3ced8d418e6c34548f5e2789f9da619 Gitweb: https://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git//15a73839e3ced8d418e6c34548f5e2789f9da619 Author: Daniel Lezcano <daniel.lezcano@linaro.org> AuthorDate: Fri, 05 Aug 2022 17:38:31 +02:00 Committer: Daniel Lezcano <daniel.lezcano@linaro.org> CommitterDate: Wed, 17 Aug 2022 14:09:39 +02:00 thermal/core: Rework the monitoring a bit The should_stop_polling() function wraps the function thermal_zone_device_is_enabled(). The monitor_thermal_zone() function checks if the thermal zone is enabled via the should_stop_polling() function. However, the instant after checking the thermal zone is enabled, this one can be disabled, so even if that reduces the race window, it does not prevent that and the monitoring can be set again with the thermal zone disabled. For this reason, the function should_stop_polling() is replaced by a direct check of the thermal zone mode with the mutex locks held, that prevents the situation described above. As the semantic is clear with the thermal_zone_is_enabled() function, we can remove the should_stop_polling() function and replace the check with the former function. While at it, reorder the checks to improve the readability of the monitor_thermal_zone() function. In the future, the thermal_zone_device_disable() and the thermal_zone_device_enable() functions should unset / set the polling timer directly instead of relying on the next thermal_zone_device_update() call to do that. That will make a synchronous thermal zone mode change but the locking scheme should be double checked for that which out of the scope of this change. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20220805153834.2510142-2-daniel.lezcano@linaro.org --- drivers/thermal/thermal_core.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-)