Re: [Outreachy kernel] [PATCH v3] staging: iio: meter: add check on return variables

[Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>]

On Tue, Mar 03, 2015 at 07:01:47AM -0500, Julia Lawall wrote:
> On Tue, 3 Mar 2015, Aya Mahfouz wrote:
> 
> > Adds checks on variables that are used to return values. If
> > the value is less than zero, this indicates that an error
> > occured and hence a message is printed through dev_err. Labels
> > have been added too, since the check is done more than once.
> 
> How did you find the functions that have this property?
>
Do you mean that I should state that I found it using coccinelle?
> julia
> 
> > Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
> > ---
> > v1: added checks on last calls only.
> > v2: added checks on all calls that return values along with labels.
> > v3: added changelog that was missed in v2.
> >
> >  drivers/staging/iio/meter/ade7758_core.c | 35 ++++++++++++++++++++------------
> >  1 file changed, 22 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/staging/iio/meter/ade7758_core.c b/drivers/staging/iio/meter/ade7758_core.c
> > index 70e96b2..cab392f 100644
> > --- a/drivers/staging/iio/meter/ade7758_core.c
> > +++ b/drivers/staging/iio/meter/ade7758_core.c
> > @@ -303,14 +303,18 @@ static int ade7758_reset(struct device *dev)
> >  	int ret;
> >  	u8 val;
> >
> > -	ade7758_spi_read_reg_8(dev,
> > -			ADE7758_OPMODE,
> > -			&val);
> > +	ret = ade7758_spi_read_reg_8(dev, ADE7758_OPMODE, &val);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to read from device");
> > +		goto error_ret;
> > +	}
> >  	val |= 1 << 6; /* Software Chip Reset */
> > -	ret = ade7758_spi_write_reg_8(dev,
> > -			ADE7758_OPMODE,
> > -			val);
> > -
> > +	ret = ade7758_spi_write_reg_8(dev, ADE7758_OPMODE, val);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to reset device");
> > +		goto error_ret;
> > +	}
> > +error_ret:
> >  	return ret;
> >  }
> >
> > @@ -444,14 +448,19 @@ static int ade7758_stop_device(struct device *dev)
> >  	int ret;
> >  	u8 val;
> >
> > -	ade7758_spi_read_reg_8(dev,
> > -			ADE7758_OPMODE,
> > -			&val);
> > +	ret = ade7758_spi_read_reg_8(dev, ADE7758_OPMODE, &val);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to read from device");
> > +		goto error_ret;
> > +	}
> >  	val |= 7 << 3;  /* ADE7758 powered down */
> > -	ret = ade7758_spi_write_reg_8(dev,
> > -			ADE7758_OPMODE,
> > -			val);
> > +	ret = ade7758_spi_write_reg_8(dev, ADE7758_OPMODE, val);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to stop device");
> > +		goto error_ret;
> > +	}
> >
> > +error_ret:
> >  	return ret;
> >  }
> >
> > --
> > 1.9.3
> >
> >
> > --
> > Kind Regards,
> > Aya Saif El-yazal Mahfouz
> >
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-- 
Kind Regards,
Aya Saif El-yazal Mahfouz