[PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[Gustavo A. R. Silva]

Remove unnecessary static on local variables syscon_regmap.
Such variables are initialized before being used, on every
execution path throughout the functions. The static has no
benefit and, removing it reduces the object file size.

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

@bad exists@
position p;
identifier x;
type T;
@@

static T x@p;
...
x = <+...x...+>

@@
identifier x;
expression e;
type T;
position p != bad.p;
@@

-static
 T x@p;
 ... when != x
     when strict
?x = e;

In the following log you can see the difference in the object file size.
This log is the output of the size command, before and after the code
change:

before:
   text    data     bss     dec     hex filename
   3339    2104     128    5571    15c3 drivers/soc/versatile/soc-realview.o

after:
   text    data     bss     dec     hex filename
   3321    2048      64    5433    1539 drivers/soc/versatile/soc-realview.o

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/soc/versatile/soc-realview.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/versatile/soc-realview.c b/drivers/soc/versatile/soc-realview.c
index 282e371..caf698e 100644
--- a/drivers/soc/versatile/soc-realview.c
+++ b/drivers/soc/versatile/soc-realview.c
@@ -85,7 +85,7 @@ static struct device_attribute realview_build_attr =
 
 static int realview_soc_probe(struct platform_device *pdev)
 {
-	static struct regmap *syscon_regmap;
+	struct regmap *syscon_regmap;
 	struct soc_device *soc_dev;
 	struct soc_device_attribute *soc_dev_attr;
 	struct device_node *np = pdev->dev.of_node;
-- 
2.5.0

Re: [PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[Linus Walleij]

On Thu, Jul 20, 2017 at 12:40 AM, Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:

> Remove unnecessary static on local variables syscon_regmap.
> Such variables are initialized before being used, on every
> execution path throughout the functions. The static has no
> benefit and, removing it reduces the object file size.
>
> This issue was detected using Coccinelle and the following
> semantic patch:
>
> @bad exists@
> position p;
> identifier x;
> type T;
> @@
>
> static T x@p;
> ...
> x = <+...x...+>
>
> @@
> identifier x;
> expression e;
> type T;
> position p != bad.p;
> @@
>
> -static
>  T x@p;
>  ... when != x
>      when strict
> ?x = e;
>
> In the following log you can see the difference in the object file size.
> This log is the output of the size command, before and after the code
> change:
>
> before:
>    text    data     bss     dec     hex filename
>    3339    2104     128    5571    15c3 drivers/soc/versatile/soc-realview.o
>
> after:
>    text    data     bss     dec     hex filename
>    3321    2048      64    5433    1539 drivers/soc/versatile/soc-realview.o
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Acked-by: Linus Walleij <linus.walleij@linaro.org>

You probably want to funnel this patch through the ARM SoC tree.

(If nothing else works, send as separate patch to arm@kernel.org)

Yours,
Linus Walleij

Re: [PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[Gustavo A. R. Silva]

On 08/02/2017 06:59 AM, Linus Walleij wrote:
> On Thu, Jul 20, 2017 at 12:40 AM, Gustavo A. R. Silva
> <gustavo@embeddedor.com> wrote:
>
>> Remove unnecessary static on local variables syscon_regmap.
>> Such variables are initialized before being used, on every
>> execution path throughout the functions. The static has no
>> benefit and, removing it reduces the object file size.
>>
>> This issue was detected using Coccinelle and the following
>> semantic patch:
>>
>> @bad exists@
>> position p;
>> identifier x;
>> type T;
>> @@
>>
>> static T x@p;
>> ...
>> x = <+...x...+>
>>
>> @@
>> identifier x;
>> expression e;
>> type T;
>> position p != bad.p;
>> @@
>>
>> -static
>>  T x@p;
>>  ... when != x
>>      when strict
>> ?x = e;
>>
>> In the following log you can see the difference in the object file size.
>> This log is the output of the size command, before and after the code
>> change:
>>
>> before:
>>    text    data     bss     dec     hex filename
>>    3339    2104     128    5571    15c3 drivers/soc/versatile/soc-realview.o
>>
>> after:
>>    text    data     bss     dec     hex filename
>>    3321    2048      64    5433    1539 drivers/soc/versatile/soc-realview.o
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
>
> You probably want to funnel this patch through the ARM SoC tree.
>
> (If nothing else works, send as separate patch to arm@kernel.org)
>

OK, I'll do that. I'll add your ACK and CC you.

Thanks!
-- 
Gustavo A. R. Silva

Re: [PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[Arnd Bergmann]

On Wed, Aug 2, 2017 at 1:59 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Thu, Jul 20, 2017 at 12:40 AM, Gustavo A. R. Silva
> <gustavo@embeddedor.com> wrote:
>
>> Remove unnecessary static on local variables syscon_regmap.
>> Such variables are initialized before being used, on every
>> execution path throughout the functions. The static has no
>> benefit and, removing it reduces the object file size.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Good catch!

> Acked-by: Linus Walleij <linus.walleij@linaro.org>

Applied to next/cleanup with your Ack, thanks!

     Arnd

[PATCH] soc: versatile: remove unnecessary static in realview_soc_probe()

[Gustavo A. R. Silva]

Remove unnecessary static on local variable syscon_regmap.
Such variable is initialized before being used,
on every execution path throughout the function.
The static has no benefit and, removing it reduces
the code size.

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

@bad exists@
position p;
identifier x;
type T;
@@

static T x@p;
...
x = <+...x...+>

@@
identifier x;
expression e;
type T;
position p != bad.p;
@@

-static
 T x@p;
 ... when != x
     when strict
?x = e;

In the following log you can see the difference in the code size. Also,
there is a significant difference in then bss segment. This log is the
output of the size command, before and after the code change:

before:
   text    data     bss     dec     hex filename
   3339    2104     128    5571    15c3 drivers/soc/versatile/soc-realview.o

after:
   text    data     bss     dec     hex filename
   3321    2048      64    5433    1539 drivers/soc/versatile/soc-realview.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/soc/versatile/soc-realview.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/versatile/soc-realview.c b/drivers/soc/versatile/soc-realview.c
index 282e371..caf698e 100644
--- a/drivers/soc/versatile/soc-realview.c
+++ b/drivers/soc/versatile/soc-realview.c
@@ -85,7 +85,7 @@ static struct device_attribute realview_build_attr =
 
 static int realview_soc_probe(struct platform_device *pdev)
 {
-	static struct regmap *syscon_regmap;
+	struct regmap *syscon_regmap;
 	struct soc_device *soc_dev;
 	struct soc_device_attribute *soc_dev_attr;
 	struct device_node *np = pdev->dev.of_node;
-- 
2.5.0