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SubjectRe: [PATCH V2] thermal: Fix locking in cooling device sysfs update cur_state
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On 11/27/2018 05:43 PM, Thara Gopinath wrote:
> 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>
> ---
>
> V1->V2: Rearranged the code as per Daniel's review comment

Hi Eduardo, Daniel

Any comments on this ?

Regards
Thara

>
> 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 2241cea..aa99edb 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
>



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