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

Michael Schmitz
2023-07-24T20:26:46Z

Thanks William,

On 24/07/23 23:42, William R Sowerbutts wrote:
>> I was left with the impression that the Q40 does not actually have the IDE
>> controller on the ISA bus.
> This is mistaken.
>
> IDE is definitely accessed over the ISA bus.
>
> There is some documentation on the Q40/Q60 hardware here:
> http://www.q40.de/download/harddoc.pdf
Noted - hadn't seen this one before.
>
> The motherboard integrates the CPU, DRAM, video DRAM and display controller,
> audio DACs, RTC, interrupt controller, keyboard controller, and an LED
> output.

No disk controller on the main board - that's where my error originated.

Note that this also means that the address hardcoded for IDE may be
incorrect (AFAIR, IDE cards could have their IO base reassigned by
firmware).

> There are two ISA slots where all other I/O devices are connected. These are
> described (concisely!) on page 7 of the linked manual:
>
> 8-bit ISA I/O cycles are performed for CPU byte accesses to 0xFF400001 + 4 * ISA address
>
> 16-bit ISA I/O cycles are performed for CPU word accesses to 0xFF400000 + 4 * ISA address
>
> 8-bit ISA memory cycles are performed for CPU byte accesses to 0xFF800001 + 4 * ISA address
>
> 16-bit ISA memory cycles are performed for CPU word accesses to 0xFF800000 + 4 * ISA address
Yep, that much is evident from the Q40 address translation scheme. But a
similar sort of scheme is used on other m68k platforms to wire up
peripherals that were originally designed for Intel systems, and these
are not connected through an ISA bus.
> I understand that the machines originally shipped with a 16-bit ISA card
> based on the W83787IF "PC super I/O" chip, integrating a floppy controller,
> IDE interface, game port, parallel port, and two 16550A UARTs.
OK.
>
> My Q40 came without this card, so I am using a card based on the similar
> W83757 chip (the serial ports are 16450 instead of 16550A, it doesn't support
> the fancy EPP/ECP parallel port modes).
>
>>>> It might be a good idea to verify that IDE works in v5.13
>>> Yes, please do.
> It did.
>
>> And please also verify it's broken after 44b1fbc0f5f30e66 was applied.
> I will try to do that!

Probably just try v5.14 - in my tree, 44b1fbc0f5f30e66 came on top of
5.13-rc2 so 5.14 ought to have it applied (but rather check, just the same).

Cheers,

Michael

>
> Thanks
>
> Will
>
> _________________________________________________________________________
> William R Sowerbutts will@sowerbutts.com
> "Carpe post meridiem" http://sowerbutts.com
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> (m=-1;m<7;putchar(m++/6&c%3/2?10:s[c]-31&1<<m?42:32));}
>