RE: [PATCH 1/4] iio: adc: xilinx: Rename 'channels' variable name to 'iio_xadc_channels'

[Manish Narani]

Hi Lars,

> -----Original Message-----
> From: Lars-Peter Clausen [mailto:lars@xxxxxxxxxx]
> Sent: Wednesday, July 18, 2018 4:49 PM
> To: Manish Narani <MNARANI@xxxxxxxxxx>; jic23@xxxxxxxxxx;
> knaack.h@xxxxxx; pmeerw@xxxxxxxxxx; Michal Simek
> <michals@xxxxxxxxxx>; linux-iio@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud
> <sgoud@xxxxxxxxxx>; Joe Perches <joe@xxxxxxxxxxx>
> Subject: Re: [PATCH 1/4] iio: adc: xilinx: Rename 'channels' variable name to
> 'iio_xadc_channels'
> 
> On 07/18/2018 01:12 PM, Manish Narani wrote:
> > This patch fix the following checkpatch warning in xadc driver.
> > - Reusing the krealloc arg is almost always a bug.
> >
> > Renamed the 'channels' variable as 'iio_xadc_channels' to fix the
> > above warning.
> >
> 
> This is a bug in checkpatch and should be fixed in checkpatch. The code is not
> actually re-using the parameter. channels and xadc_channels are independent
> variables, just checkpatch somehow does not realize this.
I agree with you on this. Initially I presumed the checkpatch to be giving genuine
warning but now I am sure that this is certainly the checkpatch script issue.
In that case should we keep this code change?
Please suggest.

Thanks,
Manish

> 
> > Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
> > ---
> >  drivers/iio/adc/xilinx-xadc-core.c | 16 +++++++++-------
> >  1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/iio/adc/xilinx-xadc-core.c
> > b/drivers/iio/adc/xilinx-xadc-core.c
> > index d4f21d1..27b45df 100644
> > --- a/drivers/iio/adc/xilinx-xadc-core.c
> > +++ b/drivers/iio/adc/xilinx-xadc-core.c
> > @@ -1040,7 +1040,7 @@ static int xadc_parse_dt(struct iio_dev *indio_dev,
> struct device_node *np,
> >  	unsigned int *conf)
> >  {
> >  	struct xadc *xadc = iio_priv(indio_dev);
> > -	struct iio_chan_spec *channels, *chan;
> > +	struct iio_chan_spec *iio_xadc_channels, *chan;
> >  	struct device_node *chan_node, *child;
> >  	unsigned int num_channels;
> >  	const char *external_mux;
> > @@ -1083,12 +1083,13 @@ static int xadc_parse_dt(struct iio_dev
> *indio_dev, struct device_node *np,
> >  		*conf |= XADC_CONF0_MUX |
> XADC_CONF0_CHAN(ext_mux_chan);
> >  	}
> >
> > -	channels = kmemdup(xadc_channels, sizeof(xadc_channels),
> GFP_KERNEL);
> > -	if (!channels)
> > +	iio_xadc_channels = kmemdup(xadc_channels, sizeof(xadc_channels),
> > +				    GFP_KERNEL);
> > +	if (!iio_xadc_channels)
> >  		return -ENOMEM;
> >
> >  	num_channels = 9;
> > -	chan = &channels[9];
> > +	chan = &iio_xadc_channels[9];
> >
> >  	chan_node = of_get_child_by_name(np, "xlnx,channels");
> >  	if (chan_node) {
> > @@ -1119,11 +1120,12 @@ static int xadc_parse_dt(struct iio_dev
> *indio_dev, struct device_node *np,
> >  	of_node_put(chan_node);
> >
> >  	indio_dev->num_channels = num_channels;
> > -	indio_dev->channels = krealloc(channels, sizeof(*channels) *
> > -					num_channels, GFP_KERNEL);
> > +	indio_dev->channels = krealloc(iio_xadc_channels,
> > +				       sizeof(*iio_xadc_channels) *
> > +				       num_channels, GFP_KERNEL);
> >  	/* If we can't resize the channels array, just use the original */
> >  	if (!indio_dev->channels)
> > -		indio_dev->channels = channels;
> > +		indio_dev->channels = iio_xadc_channels;
> >
> >  	return 0;
> >  }
> >