Several questions regarding ARCH_S3C2410

[Ben Dooks]

On Fri, Jun 18, 2010 at 11:43:37AM +0800, Eric Miao wrote:
> Hi Ben,
> 
> While working towards a unified kernel, I found that ARCH_S3C2410 actually
> includes multiple mach-* already.
> 
> linux-2.6$ git grep "ARCH_S3C2410" arch/arm/Makefile
> arch/arm/Makefile:machine-$(CONFIG_ARCH_S3C2410)	:= s3c2410 s3c2400
> s3c2412 s3c2416 s3c2440 s3c2443
> 
> There are several questions though:
> 
> 1. It looks like only s3c2410 is significant, so all the common definitions
>    like PHYS_OFFSET are actually same across all mach-s3c24* (except for
>    s3c24a0) ? Yet I've found arch/arm/mach-s3c2400/include/mach/memory.h,
>    where a different PHYS_OFFSET is defined, just feel a bit confused.

You can safely ignore the s3c24a0 for the moment, there's no-one interested
in actually getting it submitted.
 
> 2. So except for s3c24a0, theretically, it's possible to combine all these
>    mach into something mach-s3c24xx?

Theoretically yes, practically leave it alone.

> 3. When trying building of s3c2410_defconfig, there are a lot complaints
>    about re-definitions of {in,out}[s]{b,w,l}.  Taking a look into io.h,
>    I'm wondering if it's possible to use those definitions in asm/io.h?
>    (possibly with a customized __io())
> 
> In file included from linux-2.6/include/linux/scatterlist.h:8,
>                  from linux-2.6/include/linux/dma-mapping.h:7,
>                  from linux-2.6/include/linux/dmaengine.h:26,
>                  from linux-2.6/include/linux/skbuff.h:30,
>                  from linux-2.6/lib/kobject_uevent.c:24:
> linux-2.6/arch/arm/include/asm/io.h:137: warning: "outb" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:196: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:138: warning: "outw" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:197: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:140: warning: "outl" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:198: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:143: warning: "inb" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:193: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:144: warning: "inw" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:194: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:146: warning: "inl" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:195: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:149: warning: "outsb" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:207: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:150: warning: "outsw" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:208: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:151: warning: "outsl" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:209: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:153: warning: "insb" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:203: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:154: warning: "insw" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:204: note: this is
> the location of the previous definition
> linux-2.6/arch/arm/include/asm/io.h:155: warning: "insl" redefined
> linux-2.6/arch/arm/mach-s3c2410/include/mach/io.h:205: note: this is
> the location of the previous definition

that's something for you to sort out.

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.