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

Finn Thain
2023-08-13T07:38:08Z

Michael, William,

On Sun, 13 Aug 2023, Michael Schmitz wrote:

> Am 28.07.23 um 11:47 schrieb Finn Thain:
> > On Thu, 27 Jul 2023, Michael Schmitz wrote:
> >
> >>>> And yes, I'm painfully aware the m68k low level IO code is becoming
> >>>> a bit of a maintainance legacy, in no small part due to my hacks
> >>>> around Atari EtherNEC.
> >>>>
> >>> I guess you and I both can share the blame for 44b1fbc0f5f30e66...
> >>>
> >>> Anyway, you make a good point about on-going maintenance. Do you
> >>> think that by supporting standard ISA drivers we might actually
> >>> reduce the ideosyncracies in m68k IO code?
> >> You and DaveM ought to have a chat about that - abstracting the
> >> legacy drivers from the ISA constraints was his preferred option when
> >> I last attempted to get the Gayle network driver patches merged. When
> >> I say 'preferred', I'm probably understating a little.
> >>
> > A discussion with maintainers probably won't get far without working
> > code to look at. Perhaps William will send an RFC patch to illustrate
> > his approach.
>
> Haven't seen anything yet, so I've just sent a patch switching
> pata_falcon.c to use the IO resources instead of the memory resources.

Thanks for sending that.

> Survived compile and ARAnyM boot tests only so far. I've checked and
> confirmed the entire 0xffxxxxx range is mapped transparent in head.S for
> Q40 so I don't see what else might be missing.
>

In the message that Geert originally forwarded, William was quoted as
saying it was necessary to "fix up the pata_falcon_data_xfer function". He
also said that using the IO port resources "causes the ioread8/iowrite8
functions to complain loudly".
https://lore.kernel.org/linux-m68k/CAMuHMdUU62jjunJh9cqSqHT87B0H0A4udOOPs=WN7WZKpcagVA@mail.gmail.com/

I think your patch is taking the same approach and may run into the same
issues... I guess we shall see when William tests it.

> Please have a look and test if possible. Haven't yet bothered
> linux-block or linux-ide... the patch still needs a Fixes: and other
> trimmings so isn't ready for submission anyway.
>

Right. You'll want to run checkpatch.pl on it at some stage.