Messages in this thread | | | Subject | Re: [PATCH 0/1] m68k: Handle HAS_IOPORT dependencies | From | Michael Schmitz <> | Date | Sat, 6 Apr 2024 07:36:26 +1300 |
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Hi Geert,
Am 05.04.2024 um 23:16 schrieb Geert Uytterhoeven: > Hi Arnd, > > 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.
Just saying ...
Michael
> > arch/m68k/include/asm/floppy.h on Sun-3x might be the only offender? > > Gr{oetje,eeting}s, > > Geert >
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