[PATCH] pinctrl: consumer: use correct retval for placeholder functions

[PATCH] pinctrl: consumer: use correct retval for placeholder functions

[Wolfram Sang]

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

These functions are supposed to return an error pointer, not NULL.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 include/linux/pinctrl/consumer.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/pinctrl/consumer.h b/include/linux/pinctrl/consumer.h
index e96eea7a835c..5e949122529d 100644
--- a/include/linux/pinctrl/consumer.h
+++ b/include/linux/pinctrl/consumer.h
@@ -83,7 +83,7 @@ static inline int pinctrl_gpio_direction_output(unsigned gpio)
 
 static inline struct pinctrl * __must_check pinctrl_get(struct device *dev)
 {
-	return NULL;
+	return ERR_PTR(-ENOSYS);
 }
 
 static inline void pinctrl_put(struct pinctrl *p)
@@ -94,7 +94,7 @@ static inline struct pinctrl_state * __must_check pinctrl_lookup_state(
 							struct pinctrl *p,
 							const char *name)
 {
-	return NULL;
+	return ERR_PTR(-ENOSYS);
 }
 
 static inline int pinctrl_select_state(struct pinctrl *p,
@@ -109,7 +109,7 @@ static inline void pinctrl_deselect_state(struct pinctrl *p)
 
 static inline struct pinctrl * __must_check devm_pinctrl_get(struct device *dev)
 {
-	return NULL;
+	return ERR_PTR(-ENOSYS);
 }
 
 static inline void devm_pinctrl_put(struct pinctrl *p)
-- 
2.1.3

Re: [PATCH] pinctrl: consumer: use correct retval for placeholder functions

[Linus Walleij]

On Tue, Dec 16, 2014 at 10:59 AM, Wolfram Sang <wsa@the-dreams.de> wrote:

> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
>
> These functions are supposed to return an error pointer, not NULL.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Worried that some driver may depend on this behaviour, but
patch applied anyway, let's deal with it.

Yours,
Linus Walleij

Re: [PATCH] pinctrl: consumer: use correct retval for placeholder functions

[Wolfram Sang]

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Hi Linus,

> > From: Wolfram Sang <wsa+renesas@sang-engineering.com>
> >
> > These functions are supposed to return an error pointer, not NULL.
> >
> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> 
> Worried that some driver may depend on this behaviour, but
> patch applied anyway, let's deal with it.

I sent a similar patch to Russell for the clk API and he rightfully
NAKed it. NULL is a valid cookie from clk_get and the whole clk API is
able to deal with NULL. That ensures that for !HAVE_CLK, clk_get is
still successful and won't fail driver_probe while the other clk API
functions don't really do anything. If the gpio API is similar to that,
we should revert my patch.

Sorry for the nuisance,

   Wolfram


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Re: [PATCH] pinctrl: consumer: use correct retval for placeholder functions

[Linus Walleij]

On Mon, Feb 9, 2015 at 4:00 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
> Hi Linus,
>
>> > From: Wolfram Sang <wsa+renesas@sang-engineering.com>
>> >
>> > These functions are supposed to return an error pointer, not NULL.
>> >
>> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
>>
>> Worried that some driver may depend on this behaviour, but
>> patch applied anyway, let's deal with it.
>
> I sent a similar patch to Russell for the clk API and he rightfully
> NAKed it. NULL is a valid cookie from clk_get and the whole clk API is
> able to deal with NULL. That ensures that for !HAVE_CLK, clk_get is
> still successful and won't fail driver_probe while the other clk API
> functions don't really do anything. If the gpio API is similar to that,
> we should revert my patch.

OK reverted for fixes, no big deal.

Yours,
Linus Walleij