Re: [PATCH v3 5/7] Input: iqs7222 - protect against undefined slider size

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

On sam., oct. 22, 2022 at 19:57, Jeff LaBundy <jeff@labundy.com> wrote:

> Select variants of silicon do not define a default slider size, in
> which case the size must be specified in the device tree. If it is
> not, the axis's maximum value is reported as 65535 due to unsigned
> integer overflow.
>
> To solve this problem, move the existing zero-check outside of the
> conditional block that checks whether the property is present.
>
> Fixes: e505edaedcb9 ("Input: add support for Azoteq IQS7222A/B/C")
> Signed-off-by: Jeff LaBundy <jeff@labundy.com>

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

> ---
> Changes in v3:
>  - None
>
> Changes in v2:
>  - Rebased to account for changes earlier in series
>
>  drivers/input/misc/iqs7222.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/misc/iqs7222.c b/drivers/input/misc/iqs7222.c
> index a5c08b1d9c9b..6af25dfd1d2a 100644
> --- a/drivers/input/misc/iqs7222.c
> +++ b/drivers/input/misc/iqs7222.c
> @@ -2024,7 +2024,7 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
>  
>  	error = fwnode_property_read_u32(sldr_node, "azoteq,slider-size", &val);
>  	if (!error) {
> -		if (!val || val > dev_desc->sldr_res) {
> +		if (val > dev_desc->sldr_res) {
>  			dev_err(&client->dev, "Invalid %s size: %u\n",
>  				fwnode_get_name(sldr_node), val);
>  			return -EINVAL;
> @@ -2043,6 +2043,13 @@ static int iqs7222_parse_sldr(struct iqs7222_private *iqs7222,
>  		return error;
>  	}
>  
> +	if (!(reg_offset ? sldr_setup[3]
> +			 : sldr_setup[2] & IQS7222_SLDR_SETUP_2_RES_MASK)) {
> +		dev_err(&client->dev, "Undefined %s size\n",
> +			fwnode_get_name(sldr_node));
> +		return -EINVAL;
> +	}
> +
>  	error = fwnode_property_read_u32(sldr_node, "azoteq,top-speed", &val);
>  	if (!error) {
>  		if (val > (reg_offset ? U16_MAX : U8_MAX * 4)) {
> -- 
> 2.34.1