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Subject: Re: [PATCH] thermal/drivers/tsens: fix usage of unititialized value
To:     Yang Li <yang.lee@linux.alibaba.com>, amitk@kernel.org
Cc:     agross@kernel.org, bjorn.andersson@linaro.org, rui.zhang@intel.com,
        daniel.lezcano@linaro.org, linux-pm@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1623145299-109090-1-git-send-email-yang.lee@linux.alibaba.com>
From:   Thara Gopinath <thara.gopinath@linaro.org>
Message-ID: <3db50e86-911a-8b49-8c87-a33178754deb@linaro.org>
Date:   Fri, 11 Jun 2021 07:50:00 -0400
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On 6/8/21 5:41 AM, Yang Li wrote:
> When "tsens_version(priv) > VER_0_1" is false,
> "regmap_field_read(priv->rf[VER_MINOR], &ver_minor)" can't execute.
> So, ver_minor has no initialization and assignment before it is
> used, and we initialize it to 0.

Hi Yang,

Thanks for the patch. I have a few questions though.

1. Where do you see ver_minor being used uninitialized? AFAICT , 
ver_minor is used like below and will never be referenced if version <= 
VER_0_1
	if (tsens_version(priv) > VER_1_X &&  ver_minor > 2) {

2. Do you know whether minor versions can be read or not on tsens ips 
with verions < 0_1?

-- 
Warm Regards
Thara (She/Her/Hers)

> 
> Clean up smatch warning:
> drivers/thermal/qcom/tsens.c:896 init_common() error: uninitialized
> symbol 'ver_minor'.
> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
> ---
>   drivers/thermal/qcom/tsens.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> index 4c7ebd1..a36c43d 100644
> --- a/drivers/thermal/qcom/tsens.c
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -743,8 +743,8 @@ int __init init_common(struct tsens_priv *priv)
>   {
>   	void __iomem *tm_base, *srot_base;
>   	struct device *dev = priv->dev;
> -	u32 ver_minor;
>   	struct resource *res;
> +	u32 ver_minor = 0;
>   	u32 enabled;
>   	int ret, i, j;
>   	struct platform_device *op = of_find_device_by_node(priv->dev->of_node);
>