[PATCH] drm/bridge/tc358767: make the array ext_div static const, makes object smaller
Sam Ravnborg
sam at ravnborg.org
Thu Aug 19 17:18:25 UTC 2021
Hi Colin,
On Thu, Aug 19, 2021 at 02:38:39PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> Don't populate the array ext_div on the stack but instead it
> static const. Makes the object code smaller by 118 bytes:
>
> Before:
> text data bss dec hex filename
> 39449 17500 128 57077 def5 ./drivers/gpu/drm/bridge/tc358767.o
>
> After:
> text data bss dec hex filename
> 39235 17596 128 56959 de7f ./drivers/gpu/drm/bridge/tc358767.o
>
> (gcc version 10.3.0)
IMO a better argument is that this change prevents any accidental
changes and it align with how we define arrays in many other places.
The compiler may produce a smaller binary but that is just a side-effect
in this case.
Sam
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
> drivers/gpu/drm/bridge/tc358767.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index 23a6f90b694b..599c23759400 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -468,7 +468,7 @@ static int tc_pxl_pll_en(struct tc_data *tc, u32 refclk, u32 pixelclock)
> int div, best_div = 1;
> int mul, best_mul = 1;
> int delta, best_delta;
> - int ext_div[] = {1, 2, 3, 5, 7};
> + static const int ext_div[] = {1, 2, 3, 5, 7};
> int best_pixelclock = 0;
> int vco_hi = 0;
> u32 pxl_pllparam;
> --
> 2.32.0
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