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Date:   Fri, 18 Mar 2022 16:11:55 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Tong Zhang <ztong0001@gmail.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Alexandru Ardelean <ardeleanalex@gmail.com>,
        Jonathan Albrieux <jonathan.albrieux@gmail.com>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio:imu:bmi160: disable regulator in error path
Message-ID: <YjSTK4yun3kiulB1@smile.fi.intel.com>
References: <20220318070900.2499370-1-ztong0001@gmail.com>
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In-Reply-To: <20220318070900.2499370-1-ztong0001@gmail.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Fri, Mar 18, 2022 at 12:09:00AM -0700, Tong Zhang wrote:
> regulator should be disabled in error path as mentioned in _regulator_put()
> 
> [   16.233604] WARNING: CPU: 0 PID: 2177 at drivers/regulator/core.c:2257 _regulator_put
> [   16.240453] Call Trace:
> [   16.240572]  <TASK>
> [   16.240676]  regulator_put+0x26/0x40
> [   16.240853]  regulator_bulk_free+0x26/0x50
> [   16.241050]  release_nodes+0x3f/0x70
> [   16.241225]  devres_release_group+0x147/0x1c0
> [   16.241441]  ? bmi160_core_probe+0x175/0x3a0 [bmi160_core]

Seems legit. Currently we call it only when something else is failed afterwards.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Fixes: 5dea3fb066f0 ("iio: imu: bmi160: added regulator support")
> Signed-off-by: Tong Zhang <ztong0001@gmail.com>
> ---
>  drivers/iio/imu/bmi160/bmi160_core.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c
> index 824b5124a5f5..f12446edb5ce 100644
> --- a/drivers/iio/imu/bmi160/bmi160_core.c
> +++ b/drivers/iio/imu/bmi160/bmi160_core.c
> @@ -730,7 +730,7 @@ static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
>  
>  	ret = regmap_write(data->regmap, BMI160_REG_CMD, BMI160_CMD_SOFTRESET);
>  	if (ret)
> -		return ret;
> +		goto disable_regulator;
>  
>  	usleep_range(BMI160_SOFTRESET_USLEEP, BMI160_SOFTRESET_USLEEP + 1);
>  
> @@ -741,29 +741,34 @@ static int bmi160_chip_init(struct bmi160_data *data, bool use_spi)
>  	if (use_spi) {
>  		ret = regmap_read(data->regmap, BMI160_REG_DUMMY, &val);
>  		if (ret)
> -			return ret;
> +		goto disable_regulator;
>  	}
>  
>  	ret = regmap_read(data->regmap, BMI160_REG_CHIP_ID, &val);
>  	if (ret) {
>  		dev_err(dev, "Error reading chip id\n");
> -		return ret;
> +		goto disable_regulator;
>  	}
>  	if (val != BMI160_CHIP_ID_VAL) {
>  		dev_err(dev, "Wrong chip id, got %x expected %x\n",
>  			val, BMI160_CHIP_ID_VAL);
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto disable_regulator;
>  	}
>  
>  	ret = bmi160_set_mode(data, BMI160_ACCEL, true);
>  	if (ret)
> -		return ret;
> +		goto disable_regulator;
>  
>  	ret = bmi160_set_mode(data, BMI160_GYRO, true);
>  	if (ret)
> -		return ret;
> +		goto disable_regulator;
>  
>  	return 0;
> +
> +disable_regulator:
> +	regulator_bulk_disable(ARRAY_SIZE(data->supplies), data->supplies);
> +	return ret;
>  }
>  
>  static int bmi160_data_rdy_trigger_set_state(struct iio_trigger *trig,
> -- 
> 2.25.1
> 

-- 
With Best Regards,
Andy Shevchenko