2015-11-30 11:24:59

by Arnd Bergmann

Subject: [PATCH] backlight: adp8860: fix another uninitialized variable use

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 <[email protected]>
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 */

2015-12-01 09:39:00

by Hennerich, Michael

Subject: Re: [PATCH] backlight: adp8860: fix another uninitialized variable use

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 <[email protected]>

Acked-by: Michael Hennerich <[email protected]>

> 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;
Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin,
Margaret Seif

2015-12-22 12:45:07

by Jingoo Han

Subject: Re: [PATCH] backlight: adp8860: fix another uninitialized variable use

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 <[email protected]>
>
> Acked-by: Michael Hennerich <[email protected]>

Acked-by: Jingoo Han <[email protected]>

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;
> Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin,
> Margaret Seif