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Date:   Sun, 27 Mar 2022 17:02:02 +0100
From:   Jonathan Cameron <jic23@kernel.org>
To:     Tong Zhang <ztong0001@gmail.com>
Cc:     Lars-Peter Clausen <lars@metafoo.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Sean Nyekjaer <sean@geanix.com>,
        Alexandru Ardelean <ardeleanalex@gmail.com>,
        Jonathan Albrieux <jonathan.albrieux@gmail.com>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] iio:imu:bmi160: disable regulator in error path
Message-ID: <20220327170202.5fbe76a3@jic23-huawei>
In-Reply-To: <20220327165336.799db3ac@jic23-huawei>
References: <20220318070900.2499370-1-ztong0001@gmail.com>
        <20220327154005.806049-1-ztong0001@gmail.com>
        <20220327165336.799db3ac@jic23-huawei>
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On Sun, 27 Mar 2022 16:53:36 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sun, 27 Mar 2022 08:40:05 -0700
> Tong Zhang <ztong0001@gmail.com> wrote:
> 
> > Regulator should be disabled in error path as mentioned in _regulator_put().
> > Also disable accel if gyro cannot be enabled.
> > 
> > [   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]
> > 
> > Fixes: 5dea3fb066f0 ("iio: imu: bmi160: added regulator support")
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Signed-off-by: Tong Zhang <ztong0001@gmail.com>  
> oops. Raced with you ;)
> 
> Anyhow, I added the tag, so no problem.

on closer inspection b4 was clever and picked v3 up anyway.

J
> 
> Jonathan
> 
> > ---
> > v2: also disable accel when gyro fail to enable
> > v3: add tag
> >  drivers/iio/imu/bmi160/bmi160_core.c | 20 ++++++++++++++------
> >  1 file changed, 14 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c
> > index 824b5124a5f5..01336105792e 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 +741,37 @@ 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_accel;
> >  
> >  	return 0;
> > +
> > +disable_accel:
> > +	bmi160_set_mode(data, BMI160_ACCEL, false);
> > +
> > +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,  
>