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

Jeff LaBundy
2024-03-04T03:12:21Z

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