• Gustavo A. R. Silva's avatar
    gpio: altera-a10sr: constify gpio_chip structure · 1a20c3f8
    Gustavo A. R. Silva authored
    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: default avatarGustavo A. R. Silva <garsilva@embeddedor.com>
    Reviewed-by: default avatarThor Thayer <thor.thayer@linux.intel.com>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    1a20c3f8