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Date:   Tue, 5 Oct 2021 10:05:53 +0100
From:   Daniel Thompson <daniel.thompson@linaro.org>
To:     Marijn Suijten <marijn.suijten@somainline.org>
Cc:     phone-devel@vger.kernel.org, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Lee Jones <lee.jones@linaro.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        ~postmarketos/upstreaming@lists.sr.ht,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Martin Botka <martin.botka@somainline.org>,
        Jami Kettunen <jami.kettunen@somainline.org>,
        Pavel Dubrova <pashadubrova@gmail.com>,
        Kiran Gunda <kgunda@codeaurora.org>,
        Courtney Cavin <courtney.cavin@sonymobile.com>,
        Bryan Wu <cooloney@gmail.com>, linux-arm-msm@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 01/10] backlight: qcom-wled: Pass number of elements to
 read to read_u32_array
Message-ID: <20211005090553.zoqzzz4767srvwzb@maple.lan>
References: <20211004192741.621870-1-marijn.suijten@somainline.org>
 <20211004192741.621870-2-marijn.suijten@somainline.org>
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In-Reply-To: <20211004192741.621870-2-marijn.suijten@somainline.org>
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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@somainline.org>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>

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


> ---
>  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
>