[PATCH] iio: adc: mcp3564.c: Use device_for_each_child_node_scoped() to simplify error paths

[PATCH] iio: adc: mcp3564.c: Use device_for_each_child_node_scoped() to simplify error paths

[Vinícius Lima]

From: Vinícius Henrique Ferraz Lima <viniciusflima@usp.br>

Use another method to automatically release the handle on early exit,
reducing leaks.

Co-developed-by: Lucas Quaresma <lucasqml08@usp.br>
Signed-off-by: Lucas Quaresma <lucasqml08@usp.br>
Signed-off-by: Vinícius Lima <viniciusflima@usp.br>
---
 drivers/iio/adc/mcp3564.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
index 311b613b6..52c864974 100644
--- a/drivers/iio/adc/mcp3564.c
+++ b/drivers/iio/adc/mcp3564.c
@@ -998,7 +998,6 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
 	struct mcp3564_state *adc = iio_priv(indio_dev);
 	struct device *dev = &adc->spi->dev;
 	struct iio_chan_spec *channels;
-	struct fwnode_handle *child;
 	struct iio_chan_spec chanspec = mcp3564_channel_template;
 	struct iio_chan_spec temp_chanspec = mcp3564_temp_channel_template;
 	struct iio_chan_spec burnout_chanspec = mcp3564_burnout_channel_template;
@@ -1025,7 +1024,7 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
 	if (!channels)
 		return dev_err_probe(dev, -ENOMEM, "Can't allocate memory\n");
 
-	device_for_each_child_node(dev, child) {
+	device_for_each_child_node_scoped(dev, child) {
 		node_name = fwnode_get_name(child);
 
 		if (fwnode_property_present(child, "diff-channels")) {
@@ -1041,13 +1040,11 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
 			inputs[1] = MCP3564_AGND;
 		}
 		if (ret) {
-			fwnode_handle_put(child);
 			return ret;
 		}
 
 		if (inputs[0] > MCP3564_INTERNAL_VCM ||
 		    inputs[1] > MCP3564_INTERNAL_VCM) {
-			fwnode_handle_put(child);
 			return dev_err_probe(&indio_dev->dev, -EINVAL,
 					     "Channel index > %d, for %s\n",
 					     MCP3564_INTERNAL_VCM + 1,
-- 
2.45.0

Re: [PATCH] iio: adc: mcp3564.c: Use device_for_each_child_node_scoped() to simplify error paths

[Jonathan Cameron]

On Thu, 23 May 2024 13:24:35 -0300
Vinícius Lima <viniciusflima@usp.br> wrote:

> From: Vinícius Henrique Ferraz Lima <viniciusflima@usp.br>
> 
> Use another method to automatically release the handle on early exit,
> reducing leaks.
> 
> Co-developed-by: Lucas Quaresma <lucasqml08@usp.br>
> Signed-off-by: Lucas Quaresma <lucasqml08@usp.br>
> Signed-off-by: Vinícius Lima <viniciusflima@usp.br>
> ---
>  drivers/iio/adc/mcp3564.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
> index 311b613b6..52c864974 100644
> --- a/drivers/iio/adc/mcp3564.c
> +++ b/drivers/iio/adc/mcp3564.c
> @@ -998,7 +998,6 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
>  	struct mcp3564_state *adc = iio_priv(indio_dev);
>  	struct device *dev = &adc->spi->dev;
>  	struct iio_chan_spec *channels;
> -	struct fwnode_handle *child;
>  	struct iio_chan_spec chanspec = mcp3564_channel_template;
>  	struct iio_chan_spec temp_chanspec = mcp3564_temp_channel_template;
>  	struct iio_chan_spec burnout_chanspec = mcp3564_burnout_channel_template;
> @@ -1025,7 +1024,7 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
>  	if (!channels)
>  		return dev_err_probe(dev, -ENOMEM, "Can't allocate memory\n");
>  
> -	device_for_each_child_node(dev, child) {
> +	device_for_each_child_node_scoped(dev, child) {
>  		node_name = fwnode_get_name(child);
>  
>  		if (fwnode_property_present(child, "diff-channels")) {
> @@ -1041,13 +1040,11 @@ static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
>  			inputs[1] = MCP3564_AGND;
>  		}
>  		if (ret) {
> -			fwnode_handle_put(child);

Drop the {} as well if there is only one statement left after removing
the fwnode_handle_put() 

>  			return ret;
>  		}
>  
>  		if (inputs[0] > MCP3564_INTERNAL_VCM ||
>  		    inputs[1] > MCP3564_INTERNAL_VCM) {
{} can go here as well,


Otherwise looks good.

Thanks,

Jonathan


> -			fwnode_handle_put(child);
>  			return dev_err_probe(&indio_dev->dev, -EINVAL,
>  					     "Channel index > %d, for %s\n",
>  					     MCP3564_INTERNAL_VCM + 1,