On Mon, Jun 03, 2019 at 01:11:45PM +0000, Sverdlin, Alexander (Nokia - DE/Ulm) wrote: > Hi! > > On 30/05/2019 08:45, 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@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); > > This has to be mutex_unlock()... > Not only that - it is also recursive. Guenter
