[PATCH] powerpc: Fix build failure for PPC_32

[Geert Uytterhoeven]

Hi Pranith,

On Mon, Aug 18, 2014 at 9:01 PM, Pranith Kumar <bobby.prani at gmail.com> wrote:
> Fix ppc 32 build failure as reported here:
>
> http://kisskb.ellerman.id.au/kisskb/buildresult/11663513/

| arch/powerpc/include/asm/floppy.h:142:20: error: 'isa_bridge_pcidev'
undeclared (first use in this function)
| make[3]: *** [drivers/block/floppy.o] Error 1

The definition of isa_bridge_pcidev is only available if CONFIG_PCI=y...

> The error is that pci_32.o was not being built for PPC_32. Fix error by adding
> it in the Makefile. Tested using the ppc cross compiler.

... so how can adding this make the floppy.h error go away?

Note that arch/powerpc/kernel/Makefile does add
pci_$(CONFIG_WORD_SIZE).o, but only if CONFIG_PCI=y.

So, thanks for your patch, but I don't think your fix is the right solution.

However, drivers/block/floppy.o is enabled by BLK_DEV_FD, which
depends on ARCH_MAY_HAVE_PC_FDC.

arch/powerpc/Kconfig has:

config ARCH_MAY_HAVE_PC_FDC
        bool
        default !PPC_PSERIES || PCI

PCI is not set, and PPC_PSERIES is also not set, so this
defaults to y, which is obviously not correct, as floppy.h needs PCI.

As this symbol doesn't enable floppy support in-se, probably it should just
be:

config ARCH_MAY_HAVE_PC_FDC
        bool
        depends on PCI

This config line was last touched by
commit bed59275810a55500e885cbdc5c2a0507f13c00e
Author: Stephen Rothwell <sfr at canb.auug.org.au>
Date:   Sun Mar 4 17:04:44 2007 +1100

    [POWERPC] Allow pSeries to build without CONFIG_PCI

    Signed-off-by: Stephen Rothwell <sfr at canb.auug.org.au>
    Signed-off-by: Paul Mackerras <paulus at samba.org>

> Signed-off-by: Pranith Kumar <bobby.prani at gmail.com>
> Reported-by: Geert Uytterhoeven <geert at linux-m68k.org>
> CC: Andrew Morton <akpm at linux-foundation.org>
> ---
>  arch/powerpc/kernel/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index 670c312..3206ba1 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -89,7 +89,7 @@ extra-y                               += vmlinux.lds
>
>  obj-$(CONFIG_RELOCATABLE_PPC32)        += reloc_32.o
>
> -obj-$(CONFIG_PPC32)            += entry_32.o setup_32.o
> +obj-$(CONFIG_PPC32)            += entry_32.o setup_32.o pci_32.o
>  obj-$(CONFIG_PPC64)            += dma-iommu.o iommu.o
>  obj-$(CONFIG_KGDB)             += kgdb.o
>  obj-$(CONFIG_MODULES)          += ppc_ksyms.o

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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