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@xxxxxxxxx> --- I'm resending this patch to proper recipients this time. Sorry if the previous submission confused anybody. drivers/hwmon/pmbus/pmbus_core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index ef7ee90ee785..94adbede7912 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -268,6 +268,7 @@ int pmbus_update_fan(struct i2c_client *client, int page, int id, int rv; u8 to; + mutex_lock(&data->update_lock); from = pmbus_read_byte_data(client, page, pmbus_fan_config_registers[id]); if (from < 0) @@ -278,11 +279,15 @@ int pmbus_update_fan(struct i2c_client *client, int page, int id, rv = pmbus_write_byte_data(client, page, pmbus_fan_config_registers[id], to); if (rv < 0) - return rv; + goto out; } - return _pmbus_write_word_data(client, page, - pmbus_fan_command_registers[id], command); + rv = _pmbus_write_word_data(client, page, + pmbus_fan_command_registers[id], command); + +out: + mutex_lock(&data->update_lock); + return rv; } EXPORT_SYMBOL_GPL(pmbus_update_fan); -- 2.20.1
