[PATCH] pinctrl: bcm2835: constify gpio_chip structure
Linus Walleij
linus.walleij at linaro.org
Wed Aug 2 01:25:50 PDT 2017
On Tue, Jul 11, 2017 at 8:03 PM, Gustavo A. R. Silva
<garsilva at embeddedor.com> 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 at p = { ... };
>
> @ok@
> identifier r.i;
> expression e;
> position p;
> @@
> e = i at p;
>
> @bad@
> position p != {r.p,ok.p};
> identifier r.i;
> struct gpio_chip e;
> @@
> e at 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
> 18958 9000 128 28086 6db6 drivers/pinctrl/bcm/pinctrl-bcm2835.o
>
> after:
> text data bss dec hex filename
> 18764 8912 128 27804 6c9c drivers/pinctrl/bcm/pinctrl-bcm2835.o
>
> Signed-off-by: Gustavo A. R. Silva <garsilva at embeddedor.com>
Patch applied with Eric's ACK.
Yours,
Linus Walleij
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