Re: [PATCH] Input: iqs626a - Use common error handling code in iqs626_parse_events()

[Jeff LaBundy <jeff@labundy.com>]

Hi Markus,

On Sat, Mar 02, 2024 at 12:42:08PM +0100, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 2 Mar 2024 11:44:17 +0100
> 
> Add a jump target so that a bit of exception handling can be better reused
> at the end of this function implementation.
> 
> This issue was transformed by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  drivers/input/misc/iqs626a.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/input/misc/iqs626a.c b/drivers/input/misc/iqs626a.c
> index 0dab54d3a060..fa9570755f7b 100644
> --- a/drivers/input/misc/iqs626a.c
> +++ b/drivers/input/misc/iqs626a.c
> @@ -530,8 +530,7 @@ iqs626_parse_events(struct iqs626_private *iqs626,
>  					dev_err(&client->dev,
>  						"Invalid input type: %u\n",
>  						val);
> -					fwnode_handle_put(ev_node);
> -					return -EINVAL;
> +					goto put_fwnode;
>  				}
> 
>  				iqs626->kp_type[ch_id][i] = val;
> @@ -545,8 +544,7 @@ iqs626_parse_events(struct iqs626_private *iqs626,
>  				dev_err(&client->dev,
>  					"Invalid %s channel hysteresis: %u\n",
>  					fwnode_get_name(ch_node), val);
> -				fwnode_handle_put(ev_node);
> -				return -EINVAL;
> +				goto put_fwnode;
>  			}
> 
>  			if (i == IQS626_EVENT_DEEP_DN ||
> @@ -566,8 +564,7 @@ iqs626_parse_events(struct iqs626_private *iqs626,
>  				dev_err(&client->dev,
>  					"Invalid %s channel threshold: %u\n",
>  					fwnode_get_name(ch_node), val);
> -				fwnode_handle_put(ev_node);
> -				return -EINVAL;
> +				goto put_fwnode;
>  			}
> 
>  			if (ch_id == IQS626_CH_HALL)
> @@ -580,6 +577,10 @@ iqs626_parse_events(struct iqs626_private *iqs626,
>  	}
> 
>  	return 0;
> +
> +put_fwnode:
> +	fwnode_handle_put(ev_node);
> +	return -EINVAL;
>  }
> 
>  static noinline_for_stack int
> --
> 2.44.0
> 

Thank you for this patch, but it seems like a NAK to me. I think this is
a matter of personal preference, and according to mine, it is much more
confusing to insert a goto label after a function's primary return path
than to have 2-3 calls to fwnode_handle_put().

If you feel strongly otherwise, then I would suggest a helper function as
recommended by Dmitry in another thread. However, maybe that helper should
live in the driver core, as I suspect this driver is not the only place we
can avoid calling fwnode_handle_put() in an error path that returns an int.

Kind regards,
Jeff LaBundy