diff mbox

backlight: adp8860: fix another uninitialized variable use

Message ID 3284846.T0rzz6n1As@wuerfel (mailing list archive)
State New, archived
Headers show

Commit Message

Arnd Bergmann Nov. 30, 2015, 11:24 a.m. UTC 
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@arndb.de>
Fixes: 6be3a5a9cd91 ("backlight: adp88x0: Fix uninitialized variable use")
---
Sorry for missing this third hunk the first time around.


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Comments

Hennerich, Michael Dec. 1, 2015, 9:32 a.m. UTC | #1 
On 11/30/2015 12:24 PM, 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@arndb.de>

Acked-by: Michael Hennerich <michael.hennerich@analog.com>

> Fixes: 6be3a5a9cd91 ("backlight: adp88x0: Fix uninitialized variable use")
> ---
> Sorry for missing this third hunk the first time around.
>
> 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 */
>
Han Jingoo Dec. 22, 2015, 12:44 p.m. UTC | #2 
On Tuesday, December 01, 2015 6:33 PM, Michael Hennerich wrote:
> On 11/30/2015 12:24 PM, 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@arndb.de>
> 
> Acked-by: Michael Hennerich <michael.hennerich@analog.com>

Acked-by: Jingoo Han <jingoohan1@gmail.com>

Best regards,
Jingoo Han

> 
> > Fixes: 6be3a5a9cd91 ("backlight: adp88x0: Fix uninitialized variable use")
> > ---
> > Sorry for missing this third hunk the first time around.
> >
> > 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 */
> >
> 
> 
> --
> Greetings,
> Michael
> 
> --
> Analog Devices GmbH      Wilhelm-Wagenfeld-Str. 6      80807 Muenchen
> Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368;
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Lee Jones Jan. 11, 2016, 7:57 a.m. UTC | #3 
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@arndb.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 */
>
diff mbox

Patch

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 */