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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Fri, 5 Apr 2024 12:16:17 +0200
Message-ID: <CAMuHMdX+M1VuhDVnC9n4hCBDjHywwsByNK1w8ibazc+-8_C53A@mail.gmail.com>
Subject: Re: [PATCH 0/1] m68k: Handle HAS_IOPORT dependencies
To: Arnd Bergmann <arnd@kernel.org>
Cc: Michael Schmitz <schmitzmic@gmail.com>, Niklas Schnelle <schnelle@linux.ibm.com>, 
	linux-m68k@lists.linux-m68k.org, Heiko Carstens <hca@linux.ibm.com>, 
	linux-kernel@vger.kernel.org
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Hi Arnd,

On Wed, Apr 3, 2024 at 8:35=E2=80=AFPM Arnd Bergmann <arnd@kernel.org> wrot=
e:
> On Wed, Apr 3, 2024, at 20:11, Michael Schmitz wrote:
> > how do you propose we handle legacy drivers that do depend on
> > inb()/outb() functions (_not_ actual ISA I/O) on architectures that map
> > inb()/outb() to MMIO functions?
> >
> > (In my case, that's at least ne.c - Geert ought to have a better
> > overview what else does use inb()/outb() on m68k)
>
> If a machine provides an inb()/outb() set of operations that
> is actually used, it should set HAS_IOPORT.
>
> For the Q40, it may be better in the long run to change the
> drivers to just use MMIO directly though.

Q40 uses ISA.

Michael is worried about non-ISA drivers using inb() and friends.
At some point in time (i.e. eons ago), we were told it was better to
use in[bwl]()/read[bwl]() instead of directly dereferencing volatile
pointers...

Anyway, I don't think we have many users of inb() and friends left, and
I assume the bots should have detected any/most remaining users in Niklas'
branch...

arch/m68k/include/asm/floppy.h on Sun-3x might be the only offender?

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds