linux-kernel - [PATCH] soc: versatile: remove unnecessary static in realview_soc

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Date:   Tue, 4 Jul 2017 21:51:44 -0500
From:   "Gustavo A. R. Silva" <garsilva@...eddedor.com>
To:     linux-kernel@...r.kernel.org
Cc:     "Gustavo A. R. Silva" <garsilva@...eddedor.com>
Subject: [PATCH] soc: versatile: remove unnecessary static in
 realview_soc_probe()

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@...eddedor.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