Re: Linux 6.4.4 on m68k - Q40 - pata_falcon causes oops at boot time

Geert Uytterhoeven
2023-07-28T08:04:54Z

Hi Michael,

On Fri, Jul 28, 2023 at 9:52 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> Am 28.07.2023 um 11:47 schrieb Finn Thain:
> > What I had in mind is probably unacceptable because drivers end up having
> > to do byteswapping as happens in pata_falcon (or falconide and q40ide).
>
> Yes, but Q40 and Falcon are impossible to support any other way, and
> byte swapping the IDE interface in hardware was never repeated anywhere
> else, fortunately. We will have to keep pata_falcon around for that
> cause in any event.

Anyone remember TiVo? PPC with byte-swapped IDE interface.

> > It might be helpful to look for some precedent for this kind of thing
> > among the other big-endian platforms with ISA. MIPS Magnum is dual-endian
> > but Linux only runs in little-endian mode and the problem doesn't arise.
> > But there must be other examples. Maybe CHRP?
>
> Not all of CHRP, hearing Geert tell it. But there must be some boards
> that have an ISA bus?

It did have an ISA bus, but no ISA slots.
But the only external device on that bus was cs4232 audio.
All other ISA devices were internal to the south bridge.
http://g33rt.be/migrated/Linux/PPC/pci/isaAT1/.

Gr{oetje,eeting}s,

Geert

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