| Message ID | 20210906134040.96642-1-wangborong@cdjrlc.com |
|---|---|
| State | Accepted |
| Commit | 075667cc6c29ddc1a96af6d1f63fb673ef09b7cf |
| Headers | show |
| Series | pinctrl: renesas: no need to initialise global statics | expand |
On Mon, Sep 6, 2021 at 5:18 PM Arnd Bergmann <arnd@arndb.de> wrote: > On Mon, Sep 6, 2021 at 4:36 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > > --- a/drivers/pinctrl/renesas/core.c > > > +++ b/drivers/pinctrl/renesas/core.c > > > @@ -741,12 +741,12 @@ static int sh_pfc_suspend_init(struct sh_pfc *pfc) { return 0; } > > > #define SH_PFC_MAX_REGS 300 > > > #define SH_PFC_MAX_ENUMS 3000 > > > > > > -static unsigned int sh_pfc_errors __initdata = 0; > > > -static unsigned int sh_pfc_warnings __initdata = 0; > > > -static u32 *sh_pfc_regs __initdata = NULL; > > > -static u32 sh_pfc_num_regs __initdata = 0; > > > -static u16 *sh_pfc_enums __initdata = NULL; > > > -static u32 sh_pfc_num_enums __initdata = 0; > > > +static unsigned int sh_pfc_errors __initdata; > > > +static unsigned int sh_pfc_warnings __initdata; > > > +static u32 *sh_pfc_regs __initdata; > > > +static u32 sh_pfc_num_regs __initdata; > > > +static u16 *sh_pfc_enums __initdata; > > > +static u32 sh_pfc_num_enums __initdata; > > > > These are special, as they use __initdata. > > While dropping the initializers seems to work fine with e.g. gcc 9, > > I'm quite sure that would fail with older compiler versions, where > > the variable would be put in bss instead of initdata. > > > > See the example in include/linux/init.h, which explicitly > > initializes a variable with zero: > > > > static int init_variable __initdata = 0; > > > > Arnd: do you know in which version of gcc this was fixed? > > It seems at least 6.5.0 and later are fine (I don't have all required > > shared libs to run e.g. 5.5.0). > > I think you mixed up what happens: As far as I know, older compilers > would put variables without the =0 into .bss, but those with the explicit > =0 would end up in .data. Newer compilers treat them exactly the > same, and these variables all get put into .bss by default. This seems > to already be the case with gcc-4.1, which is the oldest one I could > easily try. > > I'm rather sure that regardless of the compiler version, adding an > explicit section attribute like the __initdata would force the section > even on the pre-4.1 compilers. I must be misremembering... Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> i.e. will queue in renesas-pinctrl-for-v5.16. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
diff --git a/drivers/pinctrl/renesas/core.c b/drivers/pinctrl/renesas/core.c index f2ab02225837..ef8ef05ba930 100644 --- a/drivers/pinctrl/renesas/core.c +++ b/drivers/pinctrl/renesas/core.c @@ -741,12 +741,12 @@ static int sh_pfc_suspend_init(struct sh_pfc *pfc) { return 0; } #define SH_PFC_MAX_REGS 300 #define SH_PFC_MAX_ENUMS 3000 -static unsigned int sh_pfc_errors __initdata = 0; -static unsigned int sh_pfc_warnings __initdata = 0; -static u32 *sh_pfc_regs __initdata = NULL; -static u32 sh_pfc_num_regs __initdata = 0; -static u16 *sh_pfc_enums __initdata = NULL; -static u32 sh_pfc_num_enums __initdata = 0; +static unsigned int sh_pfc_errors __initdata; +static unsigned int sh_pfc_warnings __initdata; +static u32 *sh_pfc_regs __initdata; +static u32 sh_pfc_num_regs __initdata; +static u16 *sh_pfc_enums __initdata; +static u32 sh_pfc_num_enums __initdata; #define sh_pfc_err(fmt, ...) \ do { \
Global static variables dont need to be initialised to 0. Because the compiler will initialise them. Signed-off-by: Jason Wang <wangborong@cdjrlc.com> --- drivers/pinctrl/renesas/core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)