2017-07-11 18:15:24

by Gustavo A. R. Silva

Subject: [PATCH] pinctrl: st: constify gpio_chip structure

This structure is only used to copy into other structure, so declare
it as const.

This issue was detected using Coccinelle and the following semantic patch:

@r disable optional_qualifier@
identifier i;
position p;
@@
static struct gpio_chip i@p = { ... };

@ok@
identifier r.i;
expression e;
position p;
@@
e = i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct gpio_chip e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct gpio_chip i = { ... };

In the following log you can see a significant difference in the code size
and data segment, hence in the dec segment. This log is the output
of the size command, before and after the code change:

before:
text data bss dec hex filename
21671 3632 128 25431 6357 drivers/pinctrl/pinctrl-st.o

after:
text data bss dec hex filename
21366 3576 128 25070 61ee drivers/pinctrl/pinctrl-st.o

Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/pinctrl/pinctrl-st.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 3ae8066..5d4789d 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1442,7 +1442,7 @@ static void st_gpio_irqmux_handler(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}

-static struct gpio_chip st_gpio_template = {
+static const struct gpio_chip st_gpio_template = {
.request = gpiochip_generic_request,
.free = gpiochip_generic_free,
.get = st_gpio_get,
--
2.5.0

2017-07-12 07:04:17

by Patrice CHOTARD

Subject: Re: [PATCH] pinctrl: st: constify gpio_chip structure

Hi Gustavo

On 07/11/2017 08:15 PM, Gustavo A. R. Silva wrote:
> This structure is only used to copy into other structure, so declare
> it as const.
>
> This issue was detected using Coccinelle and the following semantic patch:
>
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct gpio_chip i@p = { ... };
>
> @ok@
> identifier r.i;
> expression e;
> position p;
> @@
> e = i@p;
>
> @bad@
> position p != {r.p,ok.p};
> identifier r.i;
> struct gpio_chip e;
> @@
> e@i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> static
> +const
> struct gpio_chip i = { ... };
>
> In the following log you can see a significant difference in the code size
> and data segment, hence in the dec segment. This log is the output
> of the size command, before and after the code change:
>
> before:
> text data bss dec hex filename
> 21671 3632 128 25431 6357 drivers/pinctrl/pinctrl-st.o
>
> after:
> text data bss dec hex filename
> 21366 3576 128 25070 61ee drivers/pinctrl/pinctrl-st.o
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/pinctrl/pinctrl-st.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 3ae8066..5d4789d 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1442,7 +1442,7 @@ static void st_gpio_irqmux_handler(struct irq_desc *desc)
> chained_irq_exit(chip, desc);
> }
>
> -static struct gpio_chip st_gpio_template = {
> +static const struct gpio_chip st_gpio_template = {
> .request = gpiochip_generic_request,
> .free = gpiochip_generic_free,
> .get = st_gpio_get,
>

Acked-by: Patrice Chotard <[email protected]>

Thanks

2017-07-12 16:52:12

by Gustavo A. R. Silva

Subject: Re: [PATCH] pinctrl: st: constify gpio_chip structure

Hi Patrice,

Quoting Patrice CHOTARD <[email protected]>:

> Hi Gustavo
>
> On 07/11/2017 08:15 PM, Gustavo A. R. Silva wrote:
>> This structure is only used to copy into other structure, so declare
>> it as const.
>>
>> This issue was detected using Coccinelle and the following semantic patch:
>>
>> @r disable optional_qualifier@
>> identifier i;
>> position p;
>> @@
>> static struct gpio_chip i@p = { ... };
>>
>> @ok@
>> identifier r.i;
>> expression e;
>> position p;
>> @@
>> e = i@p;
>>
>> @bad@
>> position p != {r.p,ok.p};
>> identifier r.i;
>> struct gpio_chip e;
>> @@
>> e@i@p
>>
>> @depends on !bad disable optional_qualifier@
>> identifier r.i;
>> @@
>> static
>> +const
>> struct gpio_chip i = { ... };
>>
>> In the following log you can see a significant difference in the code size
>> and data segment, hence in the dec segment. This log is the output
>> of the size command, before and after the code change:
>>
>> before:
>> text data bss dec hex filename
>> 21671 3632 128 25431 6357 drivers/pinctrl/pinctrl-st.o
>>
>> after:
>> text data bss dec hex filename
>> 21366 3576 128 25070 61ee drivers/pinctrl/pinctrl-st.o
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>> ---
>> drivers/pinctrl/pinctrl-st.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> index 3ae8066..5d4789d 100644
>> --- a/drivers/pinctrl/pinctrl-st.c
>> +++ b/drivers/pinctrl/pinctrl-st.c
>> @@ -1442,7 +1442,7 @@ static void st_gpio_irqmux_handler(struct
>> irq_desc *desc)
>> chained_irq_exit(chip, desc);
>> }
>>
>> -static struct gpio_chip st_gpio_template = {
>> +static const struct gpio_chip st_gpio_template = {
>> .request = gpiochip_generic_request,
>> .free = gpiochip_generic_free,
>> .get = st_gpio_get,
>>
>
> Acked-by: Patrice Chotard <[email protected]>
>
> Thanks

Glad to help. :)

Thanks
--
Gustavo A. R. Silva

2017-08-01 13:22:25

by Linus Walleij

Subject: Re: [PATCH] pinctrl: st: constify gpio_chip structure

On Tue, Jul 11, 2017 at 8:15 PM, Gustavo A. R. Silva
<[email protected]> wrote:

> This structure is only used to copy into other structure, so declare
> it as const.
>
> This issue was detected using Coccinelle and the following semantic patch:
>
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct gpio_chip i@p = { ... };
>
> @ok@
> identifier r.i;
> expression e;
> position p;
> @@
> e = i@p;
>
> @bad@
> position p != {r.p,ok.p};
> identifier r.i;
> struct gpio_chip e;
> @@
> e@i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> static
> +const
> struct gpio_chip i = { ... };
>
> In the following log you can see a significant difference in the code size
> and data segment, hence in the dec segment. This log is the output
> of the size command, before and after the code change:
>
> before:
> text data bss dec hex filename
> 21671 3632 128 25431 6357 drivers/pinctrl/pinctrl-st.o
>
> after:
> text data bss dec hex filename
> 21366 3576 128 25070 61ee drivers/pinctrl/pinctrl-st.o
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Patch applied with Patrice's ACK.

Yours,
Linus Walleij