Re: [PATCH 1/5] Input: iqs269a - drop unused device node references

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

On Mon, Nov 28, 2022 at 21:02, Jeff LaBundy <jeff@labundy.com> wrote:

> Each call to device/fwnode_get_named_child_node() must be matched
> with a call to fwnode_handle_put() once the corresponding node is
> no longer in use. This ensures a reference count remains balanced
> in the case of dynamic device tree support.
>
> Currently, the driver does not call fwnode_handle_put() on nested
> event nodes. This patch solves this problem by adding the missing
> instances of fwnode_handle_put().
>
> As part of this change, the logic which parses each channel's key
> code is gently refactored in order to reduce the number of places
> from which fwnode_handle_put() is called.
>
> Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
> Signed-off-by: Jeff LaBundy <jeff@labundy.com>

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

> ---
>  drivers/input/misc/iqs269a.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
> index a348247d3d38..5620a009bf55 100644
> --- a/drivers/input/misc/iqs269a.c
> +++ b/drivers/input/misc/iqs269a.c
> @@ -694,7 +694,8 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
>  				dev_err(&client->dev,
>  					"Invalid channel %u threshold: %u\n",
>  					reg, val);
> -				return -EINVAL;
> +				error = -EINVAL;
> +				break;
>  			}
>  
>  			ch_reg->thresh[iqs269_events[i].th_offs] = val;
> @@ -707,7 +708,8 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
>  				dev_err(&client->dev,
>  					"Invalid channel %u hysteresis: %u\n",
>  					reg, val);
> -				return -EINVAL;
> +				error = -EINVAL;
> +				break;
>  			}
>  
>  			if (i == IQS269_EVENT_DEEP_DN ||
> @@ -721,8 +723,19 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
>  			}
>  		}
>  
> -		if (fwnode_property_read_u32(ev_node, "linux,code", &val))
> +		error = fwnode_property_read_u32(ev_node, "linux,code", &val);
> +		if (error && error != -EINVAL) {
> +			dev_err(&client->dev,
> +				"Failed to read channel %u code: %d\n", reg,
> +				error);
> +			break;
> +		}
> +
> +		fwnode_handle_put(ev_node);
> +		if (error) {
> +			error = 0;
>  			continue;
> +		}
>  
>  		switch (reg) {
>  		case IQS269_CHx_HALL_ACTIVE:
> @@ -744,7 +757,10 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
>  		iqs269->sys_reg.event_mask &= ~iqs269_events[i].mask;
>  	}
>  
> -	return 0;
> +	if (error)
> +		fwnode_handle_put(ev_node);
> +
> +	return error;
>  }
>  
>  static int iqs269_parse_prop(struct iqs269_private *iqs269)
> -- 
> 2.34.1