4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 68000a0d983f539c95ebe5dccd4f29535c7ac0af ]
Sysfs interface to update cooling device cur_state does not currently holding cooling device lock sometimes leading to stale values in cur_state if getting updated simultanelously from user space and thermal framework. Adding the proper locking code fixes this issue.
Signed-off-by: Thara Gopinath thara.gopinath@linaro.org Signed-off-by: Zhang Rui rui.zhang@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thermal/thermal_sysfs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index 2241ceae7d7f..aa99edb4dff7 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -712,11 +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) - return result; - thermal_cooling_device_stats_update(cdev, state); - return count; + if (!result) + thermal_cooling_device_stats_update(cdev, state); + + mutex_unlock(&cdev->lock); + return result ? result : count; }
static struct device_attribute