* [PATCH] gpio: altera-a10sr: constify gpio_chip structure
@ 2017-07-11 22:15 Gustavo A. R. Silva
2017-07-13 17:41 ` Thor Thayer
2017-08-02 8:29 ` Linus Walleij
0 siblings, 2 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2017-07-11 22:15 UTC (permalink / raw)
To: Thor Thayer, Linus Walleij; +Cc: linux-gpio, linux-kernel, Gustavo A. R. Silva
This structure is only used to copy into another 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
1954 600 0 2554 9fa drivers/gpio/gpio-altera-a10sr.o
after:
text data bss dec hex filename
1655 512 0 2167 877 drivers/gpio/gpio-altera-a10sr.o
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
drivers/gpio/gpio-altera-a10sr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpio/gpio-altera-a10sr.c b/drivers/gpio/gpio-altera-a10sr.c
index 16a8951..6b11f13 100644
--- a/drivers/gpio/gpio-altera-a10sr.c
+++ b/drivers/gpio/gpio-altera-a10sr.c
@@ -71,7 +71,7 @@ static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
return -EINVAL;
}
-static struct gpio_chip altr_a10sr_gc = {
+static const struct gpio_chip altr_a10sr_gc = {
.label = "altr_a10sr_gpio",
.owner = THIS_MODULE,
.get = altr_a10sr_gpio_get,
--
2.5.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] gpio: altera-a10sr: constify gpio_chip structure
2017-07-11 22:15 [PATCH] gpio: altera-a10sr: constify gpio_chip structure Gustavo A. R. Silva
@ 2017-07-13 17:41 ` Thor Thayer
2017-07-17 4:14 ` Gustavo A. R. Silva
2017-08-02 8:29 ` Linus Walleij
1 sibling, 1 reply; 4+ messages in thread
From: Thor Thayer @ 2017-07-13 17:41 UTC (permalink / raw)
To: Gustavo A. R. Silva, Linus Walleij; +Cc: linux-gpio, linux-kernel
On 07/11/2017 05:15 PM, Gustavo A. R. Silva wrote:
> This structure is only used to copy into another structure, so declare
> it as const.
<snip>
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> drivers/gpio/gpio-altera-a10sr.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-altera-a10sr.c b/drivers/gpio/gpio-altera-a10sr.c
> index 16a8951..6b11f13 100644
> --- a/drivers/gpio/gpio-altera-a10sr.c
> +++ b/drivers/gpio/gpio-altera-a10sr.c
> @@ -71,7 +71,7 @@ static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
> return -EINVAL;
> }
>
> -static struct gpio_chip altr_a10sr_gc = {
> +static const struct gpio_chip altr_a10sr_gc = {
> .label = "altr_a10sr_gpio",
> .owner = THIS_MODULE,
> .get = altr_a10sr_gpio_get,
>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] gpio: altera-a10sr: constify gpio_chip structure
2017-07-13 17:41 ` Thor Thayer
@ 2017-07-17 4:14 ` Gustavo A. R. Silva
0 siblings, 0 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2017-07-17 4:14 UTC (permalink / raw)
To: thor.thayer, Linus Walleij; +Cc: linux-gpio, linux-kernel
On 07/13/2017 12:41 PM, Thor Thayer wrote:
> On 07/11/2017 05:15 PM, Gustavo A. R. Silva wrote:
>> This structure is only used to copy into another structure, so declare
>> it as const.
>
> <snip>
>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>> drivers/gpio/gpio-altera-a10sr.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpio/gpio-altera-a10sr.c
>> b/drivers/gpio/gpio-altera-a10sr.c
>> index 16a8951..6b11f13 100644
>> --- a/drivers/gpio/gpio-altera-a10sr.c
>> +++ b/drivers/gpio/gpio-altera-a10sr.c
>> @@ -71,7 +71,7 @@ static int altr_a10sr_gpio_direction_output(struct
>> gpio_chip *gc,
>> return -EINVAL;
>> }
>> -static struct gpio_chip altr_a10sr_gc = {
>> +static const struct gpio_chip altr_a10sr_gc = {
>> .label = "altr_a10sr_gpio",
>> .owner = THIS_MODULE,
>> .get = altr_a10sr_gpio_get,
>>
> Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Thank you, Thor.
--
Gustavo A. R. Silva
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] gpio: altera-a10sr: constify gpio_chip structure
2017-07-11 22:15 [PATCH] gpio: altera-a10sr: constify gpio_chip structure Gustavo A. R. Silva
2017-07-13 17:41 ` Thor Thayer
@ 2017-08-02 8:29 ` Linus Walleij
1 sibling, 0 replies; 4+ messages in thread
From: Linus Walleij @ 2017-08-02 8:29 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Thor Thayer, linux-gpio, linux-kernel
On Wed, Jul 12, 2017 at 12:15 AM, Gustavo A. R. Silva
<garsilva@embeddedor.com> wrote:
> This structure is only used to copy into another 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
> 1954 600 0 2554 9fa drivers/gpio/gpio-altera-a10sr.o
>
> after:
> text data bss dec hex filename
> 1655 512 0 2167 877 drivers/gpio/gpio-altera-a10sr.o
>
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Patch applied with Thor's review tag.
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-08-02 8:29 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2017-07-11 22:15 [PATCH] gpio: altera-a10sr: constify gpio_chip structure Gustavo A. R. Silva
2017-07-13 17:41 ` Thor Thayer
2017-07-17 4:14 ` Gustavo A. R. Silva
2017-08-02 8:29 ` Linus Walleij
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