From f975b3399c0a35439c48b89d1afffc4d86276d0f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Thu, 27 Nov 2014 10:59:06 +0100 Subject: [PATCH] hwmon: (ina2xx) bail-out from ina2xx_probe() in case of configuration errors The return value of i2c_smbus_write_word_swapped() isn't checked in ina2xx_probe(). This leads to devices being registered even if they cannot be physically detected (e.g. device is not powered-up at boot-time). Even after restoring power to such device, it is left unconfigured as the configuration has never been actually written to the register. Error out in case of write errors in probe and notify the user. Signed-off-by: Bartosz Golaszewski [Guenter Roeck: Fixed multi-line comment style] Signed-off-by: Guenter Roeck --- drivers/hwmon/ina2xx.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index bfd3f3eeabcd..e01feba909c3 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -223,6 +223,7 @@ static int ina2xx_probe(struct i2c_client *client, struct device *hwmon_dev; long shunt = 10000; /* default shunt value 10mOhms */ u32 val; + int ret; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; @@ -247,12 +248,25 @@ static int ina2xx_probe(struct i2c_client *client, data->config = &ina2xx_config[data->kind]; /* device configuration */ - i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, - data->config->config_default); - /* set current LSB to 1mA, shunt is in uOhms */ - /* (equation 13 in datasheet) */ - i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, - data->config->calibration_factor / shunt); + ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, + data->config->config_default); + if (ret < 0) { + dev_err(dev, + "error writing to the config register: %d", ret); + return -ENODEV; + } + + /* + * Set current LSB to 1mA, shunt is in uOhms + * (equation 13 in datasheet). + */ + ret = i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, + data->config->calibration_factor / shunt); + if (ret < 0) { + dev_err(dev, + "error writing to the calibration register: %d", ret); + return -ENODEV; + } data->client = client; mutex_init(&data->update_lock);