Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Mon, 8 Apr 2024 10:19:50 +0200 | Subject | Re: [PATCH 0/1] m68k: Handle HAS_IOPORT dependencies |
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On Fri, Apr 5, 2024 at 8:36 PM Michael Schmitz <schmitzmic@gmail.com> wrote: > Am 05.04.2024 um 23:16 schrieb Geert Uytterhoeven: > > On Wed, Apr 3, 2024 at 8:35 PM Arnd Bergmann <arnd@kernel.org> wrote: > >> 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... > > All the 8390 based ethernet drivers still use inb() and friends. > > That is the main reason for the terrible hacks in > arch/m68k/include/asm/io_mm.h ... > > The last time I tried to add support for a different PCMCIA ethernet > adapter to apne.c _without_ adding to the hacks in io_mm.h, I wasn't > getting anywhere with the netdev crowd. That was ages ago, and I doubt > their enthusiasm for a rewrite of the 8390 code base to avoid using > inb() on MMIO architectures will be any better now.
As Arnd already discovered later in this thread, AMIGA_PCMCIA (sort of) selects ISA, so APNE can be considered a "real" ISA. driver, so it can keep on using inb() and friends.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68korg
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
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