update_lock is a mutex intended to protect write operations. It was not taken, however, when _pmbus_write_word_data is called from pmbus_set_samples() function which may cause problems especially when some PMBUS_VIRT_* operation is implemented as a read-modify-write cycle.
This patch makes sure the lock is held during the operation. Signed-off-by: Krzysztof Adamski <[email protected]> --- drivers/hwmon/pmbus/pmbus_core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index ef7ee90ee785..62cd213cc260 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -1946,7 +1946,9 @@ static ssize_t pmbus_set_samples(struct device *dev, if (kstrtol(buf, 0, &val) < 0) return -EINVAL; + mutex_lock(&data->update_lock); ret = _pmbus_write_word_data(client, reg->page, reg->attr->reg, val); + mutex_unlock(&data->update_lock); return ret ? : count; } -- 2.20.1
