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authorGustavo A. R. Silva <garsilva@embeddedor.com>2017-07-11 17:15:38 -0500
committerLinus Walleij <linus.walleij@linaro.org>2017-08-14 15:01:12 +0200
commit1a20c3f8e8c28357b63829ae4b16a212a4a7ef31 (patch)
treecfcadb589a96c32b2c7c4582c02951faa0c84afb /drivers
parent8340e915ea27b886f1ad52d1d68aad7cf20f802a (diff)
downloadlinux-1a20c3f8e8c28357b63829ae4b16a212a4a7ef31.tar.gz
gpio: altera-a10sr: constify gpio_chip structure
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>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-altera-a10sr.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-altera-a10sr.c b/drivers/gpio/gpio-altera-a10sr.c
index 16a8951b2bed..6b11f1314248 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,