On Thu, Aug 08, 2013 at 11:30:30AM -0600, Stephen Warren wrote: > On 08/08/2013 02:42 AM, Guenter Roeck wrote: > > On 08/07/2013 11:56 PM, Wei Ni wrote: > >> The device lm90 can be controlled by the vdd rail. > >> Adding the power control support to power on/off the vdd rail. > >> And make sure that power is enabled before accessing the device. > > >> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > > >> static int lm90_probe(struct i2c_client *client, > >> const struct i2c_device_id *id) > >> { > >> @@ -1406,6 +1434,20 @@ static int lm90_probe(struct i2c_client *client, > >> i2c_set_clientdata(client, data); > >> mutex_init(&data->update_lock); > >> > >> + data->lm90_reg = regulator_get(&client->dev, "vdd"); > > > > You should use devm_regulator_get(). Then you also don't need the call > > to regulator_put(). > > > >> + if (IS_ERR_OR_NULL(data->lm90_reg)) { > > > > The function never returns NULL except if the regulator subsystem is not > > configured, > > so IS_ERR() is more appropriate. > > > > If the regulator subsystem is not configured, you especially don't need > > or want > > to pollute the log with an error message. > > DT parsing errors should be reported. However, if there's nothing to > parse, it's not an error. > > So, I think this should report an error message *if* there is a DT > property that defines the regulator to use. If there's no property, just > use no regulator. If there is a property, it had better be possible to > parse it. > Agreed. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html