Re: [PATCH 4/4] media: nxp: use cleanup __free(fwnode_handle) simplify code

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Frank,

Thank you for the patch.

On Mon, Nov 17, 2025 at 01:58:14PM -0500, Frank Li wrote:
> Use cleanup __free(fwnode_handle) simplify code. Change to dev_err_probe()
> because replace goto with return.
> 
> Add missed "\n" at error message.
> 
> No functional change.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/media/platform/nxp/imx-mipi-csis.c    | 31 +++++++++------------------
>  drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 31 +++++++++------------------
>  2 files changed, 20 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/media/platform/nxp/imx-mipi-csis.c b/drivers/media/platform/nxp/imx-mipi-csis.c
> index ce93d868746f002c22e2f86b1e0aa84ec1a76061..d924adb406a30797b66f0094ab17e98ad44fefac 100644
> --- a/drivers/media/platform/nxp/imx-mipi-csis.c
> +++ b/drivers/media/platform/nxp/imx-mipi-csis.c
> @@ -12,6 +12,7 @@
>   *
>   */
>  
> +#include <linux/cleanup.h>
>  #include <linux/clk.h>
>  #include <linux/debugfs.h>
>  #include <linux/delay.h>
> @@ -1349,28 +1350,25 @@ static int mipi_csis_async_register(struct mipi_csis_device *csis)
>  		.bus_type = V4L2_MBUS_CSI2_DPHY,
>  	};
>  	struct v4l2_async_connection *asd;
uuu> -	struct fwnode_handle *ep;
>  	unsigned int i;
>  	int ret;
>  
>  	v4l2_async_subdev_nf_init(&csis->notifier, &csis->sd);
>  
> -	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csis->dev), 0, 0,
> -					     FWNODE_GRAPH_ENDPOINT_NEXT);
> +	struct fwnode_handle *ep __free(fwnode_handle) =
> +		fwnode_graph_get_endpoint_by_id(dev_fwnode(csis->dev), 0, 0,
> +						FWNODE_GRAPH_ENDPOINT_NEXT);

Let's avoid mixing variable declarations and code, this is a style
change that is not widely accepted (yet). You can write

	struct fwnode_handle *ep __free(fwnode_handle) = NULL;
 	struct v4l2_async_connection *asd;
	unsigned int i;
	int ret;

  	v4l2_async_subdev_nf_init(&csis->notifier, &csis->sd);

	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csis->dev), 0, 0,
					     FWNODE_GRAPH_ENDPOINT_NEXT);

>  	if (!ep)
>  		return -ENOTCONN;
>  
>  	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
>  	if (ret)
> -		goto err_parse;
> +		return ret;
>  
>  	for (i = 0; i < vep.bus.mipi_csi2.num_data_lanes; ++i) {
> -		if (vep.bus.mipi_csi2.data_lanes[i] != i + 1) {
> -			dev_err(csis->dev,
> -				"data lanes reordering is not supported");
> -			ret = -EINVAL;
> -			goto err_parse;
> -		}
> +		if (vep.bus.mipi_csi2.data_lanes[i] != i + 1)
> +			return dev_err_probe(csis->dev, -EINVAL,
> +					     "data lanes reordering is not supported\n");

To switch to dev_err_probe(), we should drop the error message in the
probe() function when mipi_csis_async_register() fails, and make sure
every error path in this function prints a message. I'd prefer splitting
that to a separate patch.

>  	}
>  
>  	csis->bus = vep.bus.mipi_csi2;
> @@ -1381,12 +1379,8 @@ static int mipi_csis_async_register(struct mipi_csis_device *csis)
>  
>  	asd = v4l2_async_nf_add_fwnode_remote(&csis->notifier, ep,
>  					      struct v4l2_async_connection);
> -	if (IS_ERR(asd)) {
> -		ret = PTR_ERR(asd);
> -		goto err_parse;
> -	}
> -
> -	fwnode_handle_put(ep);
> +	if (IS_ERR(asd))
> +		return PTR_ERR(asd);
>  
>  	csis->notifier.ops = &mipi_csis_notify_ops;
>  
> @@ -1395,11 +1389,6 @@ static int mipi_csis_async_register(struct mipi_csis_device *csis)
>  		return ret;
>  
>  	return v4l2_async_register_subdev(&csis->sd);
> -
> -err_parse:
> -	fwnode_handle_put(ep);
> -
> -	return ret;
>  }
>  
>  /* -----------------------------------------------------------------------------
> diff --git a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> index 75709161fb26a61239b94430365849e022fdc14f..94882568405db55593c5c51722db2233a64d53e4 100644
> --- a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> +++ b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <linux/bitfield.h>
> +#include <linux/cleanup.h>
>  #include <linux/clk.h>
>  #include <linux/clk-provider.h>
>  #include <linux/delay.h>
> @@ -717,28 +718,25 @@ static int imx8mq_mipi_csi_async_register(struct csi_state *state)
>  		.bus_type = V4L2_MBUS_CSI2_DPHY,
>  	};
>  	struct v4l2_async_connection *asd;
> -	struct fwnode_handle *ep;
>  	unsigned int i;
>  	int ret;
>  
>  	v4l2_async_subdev_nf_init(&state->notifier, &state->sd);
>  
> -	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(state->dev), 0, 0,
> -					     FWNODE_GRAPH_ENDPOINT_NEXT);
> +	struct fwnode_handle *ep __free(fwnode_handle) =
> +		fwnode_graph_get_endpoint_by_id(dev_fwnode(state->dev), 0, 0,
> +						FWNODE_GRAPH_ENDPOINT_NEXT);

Same comment as above.

>  	if (!ep)
>  		return -ENOTCONN;
>  
>  	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
>  	if (ret)
> -		goto err_parse;
> +		return ret;
>  
>  	for (i = 0; i < vep.bus.mipi_csi2.num_data_lanes; ++i) {
> -		if (vep.bus.mipi_csi2.data_lanes[i] != i + 1) {
> -			dev_err(state->dev,
> -				"data lanes reordering is not supported");
> -			ret = -EINVAL;
> -			goto err_parse;
> -		}
> +		if (vep.bus.mipi_csi2.data_lanes[i] != i + 1)
> +			return dev_err_probe(state->dev, -EINVAL,
> +					     "data lanes reordering is not supported\n");

And here too.

Usage of __free(fwnode_handle) looks good, it just needs to be split to
a patch of its own.

>  	}
>  
>  	state->bus = vep.bus.mipi_csi2;
> @@ -749,12 +747,8 @@ static int imx8mq_mipi_csi_async_register(struct csi_state *state)
>  
>  	asd = v4l2_async_nf_add_fwnode_remote(&state->notifier, ep,
>  					      struct v4l2_async_connection);
> -	if (IS_ERR(asd)) {
> -		ret = PTR_ERR(asd);
> -		goto err_parse;
> -	}
> -
> -	fwnode_handle_put(ep);
> +	if (IS_ERR(asd))
> +		return PTR_ERR(asd);
>  
>  	state->notifier.ops = &imx8mq_mipi_csi_notify_ops;
>  
> @@ -763,11 +757,6 @@ static int imx8mq_mipi_csi_async_register(struct csi_state *state)
>  		return ret;
>  
>  	return v4l2_async_register_subdev(&state->sd);
> -
> -err_parse:
> -	fwnode_handle_put(ep);
> -
> -	return ret;
>  }
>  
>  /* -----------------------------------------------------------------------------

-- 
Regards,

Laurent Pinchart