On Tue, May 28, 2019 at 09:08:21AM +0000, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
> The operation done in the pmbus_update_fan() function is a
> read-modify-write operation but it lacks any kind of lock protection
> which may cause problems if run more than once simultaneously. This
> patch uses an existing update_lock mutex to fix this problem.
> 
> Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>

Please use get_maintainer to find the people responsible for this file.
It is not my realm.

> +out:
> +	mutex_lock(&data->update_lock);

Despite the above, have you tested the code? This likely should be
mutex_unlock?