[PATCH] ARM: Fix the "WFI" instruction opcode definition.

[Kukjin Kim]

Dave Martin wrote:
> 

[...]

> > >> -             asm(".word      0xe320f003\n"
> > >> +             asm(__WFI
> > >
> > > Wouldn't using the actual wfi instruction fix this. There is a wfi()
> > > macro.
> > >
> > > Or just call cpu_do_idle() which will do any other things needed
> before
> > > wfi like a dsb instruction.
> > >
> > > Rob
> > >>                   :
> > >>                   :
> > >>                   : "memory", "cc");
> >
> > <Cut>
> >
> > Hi Rob,
> >     Thanks for the reply. The way you suggested is more elegant. But
> > here we worried about the version of the compiler toolchain used to
> > build the kernel. The "WFI" assembler instruction may not be
> > recognized if the toolchain is too old. Need the related ARM board
> > maintainers to confirm this.
> 
> Maybe all the exynos platforms are new enough for this not to be a
> problem?
> 
Yeah, I think there is no problem on exynos now.

> I think mach-exynos is pretty new and v7-only anyway.  If so, then it

Yes, right at the moment.

BTW, if mach-exynos includes ARMv8 later?...ARMv8 platform codes will be put
in the arch/arm/ or arch/arm/64/ if some platform codes share with ARMv7?
Just wondering...

> may be better to put
> 
> CFLAGS_hotplug.o	:= -march=armv7-a
> 
> in arch/arm/mach-exynos/Makefile, and use the real "wfi" mnemonic
> directly.  People should _really_ not be building kernels containig
> v7 board support with tools that are too old to support this.
> 
I think so...

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.