Re: [PATCH] backlight: s6e63m0: make const arrays static, reduces object code size

[Daniel Thompson]

On 12/09/17 12:45, Colin King wrote:
From: Colin Ian King <colin.k...@canonical.com>
Don't populate const arrays on the stack, instead make them
static.  Makes the object code smaller by nearly 400 bytes:

Before:
    text           data     bss     dec     hex filename
   15164           6336       0   21500    53fc 
drivers/video/backlight/s6e63m0.o

After:
    text           data     bss     dec     hex filename
   14669           6432       0   21101    526d 
drivers/video/backlight/s6e63m0.o

For future records, can you record the compiler version, architecture 
and optimization level (-O2 or -Os) to the patch header?


Signed-off-by: Colin Ian King <colin.k...@canonical.com>
---
  drivers/video/backlight/s6e63m0.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/s6e63m0.c 
b/drivers/video/backlight/s6e63m0.c
index 3c4a22a3063a..965c660b2f6b 100644
--- a/drivers/video/backlight/s6e63m0.c
+++ b/drivers/video/backlight/s6e63m0.c
@@ -446,7 +446,7 @@ static int s6e63m0_gamma_ctl(struct s6e63m0 *lcd, int gamma)
  static int s6e63m0_ldi_init(struct s6e63m0 *lcd)
  {
        int ret, i;
-       const unsigned short *init_seq[] = {
+       static const unsigned short *init_seq[] = {

I'd be inclined to throw in an extra const to help the compile spot any 
negligent maintenance in the future:

static const unsigned short * const init_seq[];


                seq_panel_condition_set,
                seq_display_condition_set,
                seq_gamma_setting,
@@ -467,7 +467,7 @@ static int s6e63m0_ldi_init(struct s6e63m0 *lcd)
  static int s6e63m0_ldi_enable(struct s6e63m0 *lcd)
  {
        int ret = 0, i;
-       const unsigned short *enable_seq[] = {
+       static const unsigned short *enable_seq[] = {
                seq_stand_by_off,
                seq_display_on,
        };