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

From: Jingoo Han
Date: Tue Dec 22 2015 - 07:45:13 EST


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@xxxxxxxx>
>
> Acked-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>

Acked-by: Jingoo Han <jingoohan1@xxxxxxxxx>

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
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