Re: [patch -mm] Make check_signature() depend on CONFIG_HAS_IOMEM

Andrew Morton
2007-06-28T18:38:48Z

On Thu, 28 Jun 2007 20:27:22 +0200 (CEST) Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> > > endif
> > >
> > > obj-$(CONFIG_GENERIC_IOMAP) += iomap.o
> > > -obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o
> > > +obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o check_signature.o
> > > obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
> > > obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
> > > lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
> >
> > We didn't think of that.
> >
> > Alas, m68k `make allmodconfig' creates CONFIG_ISA=n, CONFIG_PCI=n,
> > CONFIG_HAS_IOMEM=y, so it will still be busted.
> >
> > But this seems to be the correct fix. Perhaps m68k config needs
> > attention?
>
> Euh, I don't think this is the correct fix.
>
> CONFIG_HAS_IOMEM is apparently used in two meanings:
> 1. The architecture has support for memory mapped I/O (s390 obviously
> hasn't)
> 2. The architecture has ISA/PCI-style memory mapped I/O (readb() and
> friends)
>
> check_signature() falls under the second category.
>
> Setting NO_IOMEM on m68k will make us loose some drivers (e.g.
> drivers/video/Kconfig depends on HAS_IOMEM).
>
> Apart from many Kconfig dependencies on HAS_IOMEM, CONFIG_HAS_IOMEM is
> further only used to control the build of lib/iomap_copy.c, which
> doesn't use readb() and friends, but the __raw*() operations.
>

Well this is fun.

How to fix? Should we add a new CONFIG_HAS_IO? (IOPORTS?)