linux-kernel - Re: [PATCH] backlight: adp8860: fix another uninitialized variable use

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Message-ID: <20160111075740.GP3331@x1>
Date:	Mon, 11 Jan 2016 07:57:40 +0000
From:	Lee Jones <lee.jones@...aro.org>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Michael Hennerich <michael.hennerich@...log.com>,
	Jingoo Han <jingoohan1@...il.com>, linux-fbdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] backlight: adp8860: fix another uninitialized variable
 use

On Mon, 30 Nov 2015, Arnd Bergmann wrote:

> A recent patch I did fixed two potential uses of uninitialized
> variables in the adp8870 and adp8860 drivers. Unfortunately,
> I missed another one:
> 
> drivers/video/backlight/adp8860_bl.c: In function 'adp8860_bl_ambient_light_level_show':
> drivers/video/backlight/adp8860_bl.c:570:11: warning: 'reg_val' may be used uninitialized in this function
> 
> This does the same change as before in one additional function,
> and also changes the check for the return value in a way that
> avoids another false positive warning with a similar message.
> 
> Signed-off-by: Arnd Bergmann <arnd@...db.de>
> Fixes: 6be3a5a9cd91 ("backlight: adp88x0: Fix uninitialized variable use")
> ---
> Sorry for missing this third hunk the first time around.

Where's your diff?

Applied anyway, thanks.

> diff --git a/drivers/video/backlight/adp8860_bl.c b/drivers/video/backlight/adp8860_bl.c
> index f0d4c0324580..510e559c060e 100644
> --- a/drivers/video/backlight/adp8860_bl.c
> +++ b/drivers/video/backlight/adp8860_bl.c
> @@ -566,11 +566,13 @@ static ssize_t adp8860_bl_ambient_light_level_show(struct device *dev,
>  
>  	mutex_lock(&data->lock);
>  	error = adp8860_read(data->client, ADP8860_PH1LEVL, &reg_val);
> -	ret_val = reg_val;
> -	error |= adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
> +	if (!error) {
> +		ret_val = reg_val;
> +		error = adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
> +	}
>  	mutex_unlock(&data->lock);
>  
> -	if (error < 0)
> +	if (error)
>  		return error;
>  
>  	/* Return 13-bit conversion value for the first light sensor */
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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