Re: [PATCH 01/10] backlight: qcom-wled: Pass number of elements to read to read_u32_array

[Daniel Thompson]

On Mon, Oct 04, 2021 at 09:27:32PM +0200, Marijn Suijten wrote:
> of_property_read_u32_array takes the number of elements to read as last
> argument. This does not always need to be 4 (sizeof(u32)) but should
> instead be the size of the array in DT as read just above with
> of_property_count_elems_of_size.
> 
> To not make such an error go unnoticed again the driver now bails
> accordingly when of_property_read_u32_array returns an error.
> 
> Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3")
> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>

Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>


> ---
>  drivers/video/backlight/qcom-wled.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index d094299c2a48..6af808af2328 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -1528,11 +1528,18 @@ static int wled_configure(struct wled *wled)
>  	string_len = of_property_count_elems_of_size(dev->of_node,
>  						     "qcom,enabled-strings",
>  						     sizeof(u32));
> -	if (string_len > 0)
> -		of_property_read_u32_array(dev->of_node,
> +	if (string_len > 0) {
> +		rc = of_property_read_u32_array(dev->of_node,
>  						"qcom,enabled-strings",
>  						wled->cfg.enabled_strings,
> -						sizeof(u32));
> +						string_len);
> +		if (rc) {
> +			dev_err(dev, "Failed to read %d elements from "
> +				"qcom,enabled-strings: %d\n",
> +				string_len, rc);
> +			return -EINVAL;
> +		}
> +	}
>  
>  	return 0;
>  }
> -- 
> 2.33.0
>