Re: [PATCH v8 2/8] iio: dac: ad5686: missing NULL check on match data

[Jonathan Cameron]

On Sun, 19 Jul 2026 00:55:44 +0100
Jonathan Cameron <jonathan.cameron@xxxxxxxxxxxxxxxx> wrote:

> On Fri, 17 Jul 2026 13:28:52 +0300
> Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:
> 
> > On Fri, Jul 17, 2026 at 10:31:26AM +0100, Rodrigo Alencar wrote:  
> > > On 17/07/26 11:15, Andy Shevchenko wrote:    
> > > > On Fri, Jul 17, 2026 at 07:51:35AM +0100, Rodrigo Alencar wrote:    
> > > > > On 16/07/26 21:42, Andy Shevchenko wrote:    
> > > > > > On Thu, Jul 16, 2026 at 01:14:18PM +0100, Rodrigo Alencar via B4 Relay wrote:    
> > 
> > ...
> >   
> > > > > > >  	struct iio_dev *indio_dev;
> > > > > > >  	int ret, i;    
> > > > > > 
> > > > > > Move an assignment here as well.
> > > > > > 
> > > > > > 	chip_info = ...    
> > > > > 
> > > > > assignment? this is an input param validation    
> > > > 
> > > > Can we make sure we always get a correct one to begin with?
> > > > With that an assignment and check can be coupled together.
> > > > Also consider use -ENODATA as it's most likely comes from
> > > > driver_data.    
> > > 
> > > I suppose you are suggesting to move the check to the bus code with:
> > > 
> > > 	info = i2c_get_match_data(i2c);
> > > 	if (!info)
> > > 		return -ENODATA;
> > > 
> > > rather than here in the core/common code.    
> > 
> > Yes! This avoids layering violation and makes the API contract cleaner.  
> 
> I applied the following rather than going for a v9 for just this:
> Shout if I messed it up.
> 
> diff --git a/drivers/iio/dac/ad5686-spi.c b/drivers/iio/dac/ad5686-spi.c
> index 8abfaf8f0c46..591596a68004 100644
> --- a/drivers/iio/dac/ad5686-spi.c
> +++ b/drivers/iio/dac/ad5686-spi.c
> @@ -98,8 +98,13 @@ static const struct ad5686_bus_ops ad5686_spi_ops = {
>  
>  static int ad5686_spi_probe(struct spi_device *spi)
>  {
> -       return ad5686_probe(&spi->dev, spi_get_device_match_data(spi),
> -                           spi->modalias, &ad5686_spi_ops);
> +       const struct ad5686_chip_info *chip_info;
Renamed these to info to match the later patch that has this code anyway.

> +
> +       chip_info = spi_get_device_match_data(spi);
> +       if (!chip_info)
> +               return -ENODEV;
> +
> +       return ad5686_probe(&spi->dev, chip_info, spi->modalias, &ad5686_spi_ops);
>  }
>  
>  static const struct spi_device_id ad5686_spi_id[] = {
> diff --git a/drivers/iio/dac/ad5696-i2c.c b/drivers/iio/dac/ad5696-i2c.c
> index d49946adbde3..a6c85d0c33c9 100644
> --- a/drivers/iio/dac/ad5696-i2c.c
> +++ b/drivers/iio/dac/ad5696-i2c.c
> @@ -68,8 +68,13 @@ static const struct ad5686_bus_ops ad5686_i2c_ops = {
>  
>  static int ad5686_i2c_probe(struct i2c_client *i2c)
>  {
> -       return ad5686_probe(&i2c->dev, i2c_get_match_data(i2c),
> -                           i2c->name, &ad5686_i2c_ops);
> +       const struct ad5686_chip_info *chip_info;
> +
> +       chip_info = i2c_get_match_data(i2c);
> +       if (!chip_info)
> +               return -ENODEV;
> +
> +       return ad5686_probe(&i2c->dev, chip_info, i2c->name, &ad5686_i2c_ops);
>  }
> 
> 
> >   
> > > > > > > +	if (!chip_info)
> > > > > > > +		return -ENODEV;    
> >   
> 
>