[PATCH] thermal: Fix locking in cooling device sysfs update cur_state

[Thara Gopinath]

Sysfs interface to update cooling device cur_state does not
currently hold cooling device lock, leading to stale values
in cur_state especially if getting updated simultanelously
from user space and thermal framework. Adding the proper locking
code fixes this issue.

Signed-off-by: Thara Gopinath <thara.gopin...@linaro.org>
---
 drivers/thermal/thermal_sysfs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 2241cea..1f0c1e2 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -712,10 +712,14 @@ cur_state_store(struct device *dev, struct 
device_attribute *attr,
        if ((long)state < 0)
                return -EINVAL;
 
+       mutex_lock(&cdev->lock);
        result = cdev->ops->set_cur_state(cdev, state);
-       if (result)
+       if (result) {
+               mutex_unlock(&cdev->lock);
                return result;
+       }
        thermal_cooling_device_stats_update(cdev, state);
+       mutex_unlock(&cdev->lock);
        return count;
 }
 
-- 
2.1.4