Re: [PATCH 10/13] iio: dac: ad3552: Use __free(fwnode_handle) to replace fwnode_handle_put() calls

From: "Nuno Sá" <noname.nuno@gmail.com>
To: Jonathan Cameron <jic23@kernel.org>,
	linux-iio@vger.kernel.org,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	linux-acpi@vger.kernel.org,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Daniel Scally <djrscally@gmail.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: "Nuno Sá" <nuno.sa@analog.com>,
	"Cosmin Tanislav" <cosmin.tanislav@analog.com>,
	"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
	"Tomislav Denis" <tomislav.denis@avl.com>,
	"Marek Vasut" <marex@denx.de>,
	"Olivier Moysan" <olivier.moysan@foss.st.com>,
	"Fabrice Gasnier" <fabrice.gasnier@foss.st.com>,
	"Lad Prabhakar" <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	"Dmitry Baryshkov" <dmitry.baryshkov@linaro.org>,
	"Marijn Suijten" <marijn.suijten@somainline.org>,
	"Marius Cristea" <marius.cristea@microchip.com>,
	"Ibrahim Tilki" <Ibrahim.Tilki@analog.com>,
	"Jonathan Cameron" <Jonathan.Cameron@huawei.com>
Subject: Re: [PATCH 10/13] iio: dac: ad3552: Use __free(fwnode_handle) to replace fwnode_handle_put() calls
Date: Mon, 15 Jan 2024 11:19:11 +0100	[thread overview]
Message-ID: <a297f0c967dbf0ce9dfe441b98ea0f8a07e25597.camel@gmail.com> (raw)
In-Reply-To: <20240114172009.179893-11-jic23@kernel.org>

On Sun, 2024-01-14 at 17:20 +0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> This use of the new cleanup.h scope based freeing infrastructure allows
> us to exit directly from error conditions within the
> device_for_each_child_node(dev, child) loop. On normal exit from that
> loop no fwnode_handle reference will be held and the child pointer
> will be NULL thus making the automatically run fwnode_handle_put() a
> noop.
> 
> Removing the goto err; statements also allows more extensive use of
> dev_err_probe() further simplifying the code.
> 
> Cc: Mihail Chindris <mihail.chindris@analog.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---

Acked-by: Nuno Sa <nuno.sa@analog.com>

>  drivers/iio/dac/ad3552r.c | 50 +++++++++++++++------------------------
>  1 file changed, 19 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/iio/dac/ad3552r.c b/drivers/iio/dac/ad3552r.c
> index a492e8f2fc0f..f21c88cb480a 100644
> --- a/drivers/iio/dac/ad3552r.c
> +++ b/drivers/iio/dac/ad3552r.c
> @@ -880,7 +880,7 @@ static void ad3552r_reg_disable(void *reg)
>  static int ad3552r_configure_device(struct ad3552r_desc *dac)
>  {
>  	struct device *dev = &dac->spi->dev;
> -	struct fwnode_handle *child;
> +	struct fwnode_handle *child __free(fwnode_handle) = NULL;
>  	struct regulator *vref;
>  	int err, cnt = 0, voltage, delta = 100000;
>  	u32 vals[2], val, ch;
> @@ -951,51 +951,43 @@ static int ad3552r_configure_device(struct ad3552r_desc
> *dac)
>  
>  	device_for_each_child_node(dev, child) {
>  		err = fwnode_property_read_u32(child, "reg", &ch);
> -		if (err) {
> -			dev_err(dev, "mandatory reg property missing\n");
> -			goto put_child;
> -		}
> -		if (ch >= AD3552R_NUM_CH) {
> -			dev_err(dev, "reg must be less than %d\n",
> -				AD3552R_NUM_CH);
> -			err = -EINVAL;
> -			goto put_child;
> -		}
> +		if (err)
> +			return dev_err_probe(dev, err,
> +					     "mandatory reg property
> missing\n");
> +		if (ch >= AD3552R_NUM_CH)
> +			return dev_err_probe(dev, -EINVAL,
> +					     "reg must be less than %d\n",
> +					     AD3552R_NUM_CH);
>  
>  		if (fwnode_property_present(child, "adi,output-range-
> microvolt")) {
>  			err = fwnode_property_read_u32_array(child,
>  							     "adi,output-
> range-microvolt",
>  							     vals,
>  							     2);
> -			if (err) {
> -				dev_err(dev,
> +			if (err)
> +				return dev_err_probe(dev, err,
>  					"adi,output-range-microvolt property
> could not be parsed\n");
> -				goto put_child;
> -			}
>  
>  			err = ad3552r_find_range(dac->chip_id, vals);
> -			if (err < 0) {
> -				dev_err(dev,
> -					"Invalid adi,output-range-microvolt
> value\n");
> -				goto put_child;
> -			}
> +			if (err < 0)
> +				return dev_err_probe(dev, err,
> +						     "Invalid adi,output-
> range-microvolt value\n");
> +
>  			val = err;
>  			err = ad3552r_set_ch_value(dac,
>  						  
> AD3552R_CH_OUTPUT_RANGE_SEL,
>  						   ch, val);
>  			if (err)
> -				goto put_child;
> +				return err;
>  
>  			dac->ch_data[ch].range = val;
>  		} else if (dac->chip_id == AD3542R_ID) {
> -			dev_err(dev,
> -				"adi,output-range-microvolt is required for
> ad3542r\n");
> -			err = -EINVAL;
> -			goto put_child;
> +			return dev_err_probe(dev, -EINVAL,
> +					     "adi,output-range-microvolt is
> required for ad3542r\n");
>  		} else {
>  			err = ad3552r_configure_custom_gain(dac, child, ch);
>  			if (err)
> -				goto put_child;
> +				return err;
>  		}
>  
>  		ad3552r_calc_gain_and_offset(dac, ch);
> @@ -1003,7 +995,7 @@ static int ad3552r_configure_device(struct ad3552r_desc
> *dac)
>  
>  		err = ad3552r_set_ch_value(dac, AD3552R_CH_SELECT, ch, 1);
>  		if (err < 0)
> -			goto put_child;
> +			return err;
>  
>  		dac->channels[cnt] = AD3552R_CH_DAC(ch);
>  		++cnt;
> @@ -1021,10 +1013,6 @@ static int ad3552r_configure_device(struct ad3552r_desc
> *dac)
>  	dac->num_ch = cnt;
>  
>  	return 0;
> -put_child:
> -	fwnode_handle_put(child);
> -
> -	return err;
>  }
>  
>  static int ad3552r_init(struct ad3552r_desc *dac)