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[PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage

Started byColin King <colin.king@canonical.com>
First post2016-09-09 10:40 +0200
Last post2016-09-13 14:50 +0200
Articles 7 — 5 participants

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  [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage Colin King <colin.king@canonical.com> - 2016-09-09 10:40 +0200
    Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage Linus Walleij <linus.walleij@linaro.org> - 2016-09-12 15:50 +0200
      Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning  garbage Phil Reid <preid@electromag.com.au> - 2016-09-13 06:10 +0200
        Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage Linus Walleij <linus.walleij@linaro.org> - 2016-09-13 13:50 +0200
        Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage Arnd Bergmann <arnd@arndb.de> - 2016-09-13 14:40 +0200
          Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning  garbage Colin Ian King <colin.king@canonical.com> - 2016-09-13 14:50 +0200
          Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage Linus Walleij <linus.walleij@linaro.org> - 2016-09-13 14:50 +0200

#1479741 — [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage

FromColin King <colin.king@canonical.com>
Date2016-09-09 10:40 +0200
Subject[PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage
Message-ID<sfpvP-wL-1@gated-at.bofh.it>
From: Colin Ian King <colin.king@canonical.com>

ret is not initialized so it contains garbage.  Ensure garbage
is not returned in the case that pdata && pdata->teardown is false
by initializing ret to 0.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpio/gpio-pca953x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index cbe2824..52f3d5c 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -845,7 +845,7 @@ static int pca953x_remove(struct i2c_client *client)
 {
 	struct pca953x_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct pca953x_chip *chip = i2c_get_clientdata(client);
-	int ret;
+	int ret = 0;
 
 	if (pdata && pdata->teardown) {
 		ret = pdata->teardown(client, chip->gpio_chip.base,
-- 
2.9.3

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#1481298

FromLinus Walleij <linus.walleij@linaro.org>
Date2016-09-12 15:50 +0200
Message-ID<sgzMt-3XR-15@gated-at.bofh.it>
In reply to#1479741
On Fri, Sep 9, 2016 at 10:31 AM, Colin King <colin.king@canonical.com> wrote:

> From: Colin Ian King <colin.king@canonical.com>
>
> ret is not initialized so it contains garbage.  Ensure garbage
> is not returned in the case that pdata && pdata->teardown is false
> by initializing ret to 0.
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Patch applied.

Yours,
Linus Walleij

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#1482134 — Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage

FromPhil Reid <preid@electromag.com.au>
Date2016-09-13 06:10 +0200
SubjectRe: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage
Message-ID<sgNcK-4Tl-13@gated-at.bofh.it>
In reply to#1481298
On 12/09/2016 21:40, Linus Walleij wrote:
> On Fri, Sep 9, 2016 at 10:31 AM, Colin King <colin.king@canonical.com> wrote:
>
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> ret is not initialized so it contains garbage.  Ensure garbage
>> is not returned in the case that pdata && pdata->teardown is false
>> by initializing ret to 0.
>>
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>
> Patch applied.
G'day Linus,


I believe this does the same as Arnd Bergmanns patch from 26 Aug.
[PATCH 1/5] gpio: pca954x: fix undefined error code from remove

IMO Colin's is the cleaner solution.
Arnd's could be removed.

-- 
Regards
Phil Reid

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#1482389

FromLinus Walleij <linus.walleij@linaro.org>
Date2016-09-13 13:50 +0200
Message-ID<sgUnU-1gb-13@gated-at.bofh.it>
In reply to#1482134
On Tue, Sep 13, 2016 at 6:04 AM, Phil Reid <preid@electromag.com.au> wrote:
> On 12/09/2016 21:40, Linus Walleij wrote:
>>
>> On Fri, Sep 9, 2016 at 10:31 AM, Colin King <colin.king@canonical.com>
>> wrote:
>>
>>> From: Colin Ian King <colin.king@canonical.com>
>>>
>>> ret is not initialized so it contains garbage.  Ensure garbage
>>> is not returned in the case that pdata && pdata->teardown is false
>>> by initializing ret to 0.
>>>
>>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>>
>>
>> Patch applied.
>
> G'day Linus,
>
>
> I believe this does the same as Arnd Bergmanns patch from 26 Aug.
> [PATCH 1/5] gpio: pca954x: fix undefined error code from remove
>
> IMO Colin's is the cleaner solution.
> Arnd's could be removed.

OK you're right. I reverted Arnd's patch.

Yours,
Linus Walleij

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#1482420

FromArnd Bergmann <arnd@arndb.de>
Date2016-09-13 14:40 +0200
Message-ID<sgVai-1PB-13@gated-at.bofh.it>
In reply to#1482134
On Tuesday, September 13, 2016 12:04:00 PM CEST Phil Reid wrote:
> On 12/09/2016 21:40, Linus Walleij wrote:
> > On Fri, Sep 9, 2016 at 10:31 AM, Colin King <colin.king@canonical.com> wrote:
> >
> >> From: Colin Ian King <colin.king@canonical.com>
> >>
> >> ret is not initialized so it contains garbage.  Ensure garbage
> >> is not returned in the case that pdata && pdata->teardown is false
> >> by initializing ret to 0.
> >>
> >> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> >
> > Patch applied.
> G'day Linus,
> 
> 
> I believe this does the same as Arnd Bergmanns patch from 26 Aug.
> [PATCH 1/5] gpio: pca954x: fix undefined error code from remove
> 
> IMO Colin's is the cleaner solution.
> Arnd's could be removed.
> 

Please try to avoid adding initializations in the local variable
declaration, they just hide otherwise useful warnings when
you get a function that actually does something incorrect
in some code paths.

See also https://rusty.ozlabs.org/?p=232

	Arnd

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#1482423 — Re: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage

FromColin Ian King <colin.king@canonical.com>
Date2016-09-13 14:50 +0200
SubjectRe: [PATCH] gpio: pca953x: initialize ret to zero to avoid returning garbage
Message-ID<sgVjX-1TH-1@gated-at.bofh.it>
In reply to#1482420
On 13/09/16 13:46, Linus Walleij wrote:
> On Tue, Sep 13, 2016 at 2:31 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> 
>> Please try to avoid adding initializations in the local variable
>> declaration, they just hide otherwise useful warnings when
>> you get a function that actually does something incorrect
>> in some code paths.
> 
> Agreed, sorry for my ignorance :(
> 
> I duly corrected the git and reverted the other patch instead of yours.
> 
> Yours,
> Linus Walleij
> 
Makes sense. Thanks Linus

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#1482425

FromLinus Walleij <linus.walleij@linaro.org>
Date2016-09-13 14:50 +0200
Message-ID<sgVjX-1TH-3@gated-at.bofh.it>
In reply to#1482420
On Tue, Sep 13, 2016 at 2:31 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> Please try to avoid adding initializations in the local variable
> declaration, they just hide otherwise useful warnings when
> you get a function that actually does something incorrect
> in some code paths.

Agreed, sorry for my ignorance :(

I duly corrected the git and reverted the other patch instead of yours.

Yours,
Linus Walleij

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