Subject: Re: Realtek 8139 problem on 486.

From: Nikolai Zhubr <[email-masked]>
Date: Thu, 24 Jun 2021 20:56:44 +0300

Hi Maciej,

23.06.2021 4:04, Maciej W. Rozycki:
[...]
>   Ah, so this is the SiS 85C496/497 chipset; another one that does not have
> its southbridge visible in the PCI configuration space, perhaps because it
> doesn't put the southbridge on PCI in the first place, and instead it maps
> its configuration registers in the upper half of the northbridge's space.
> Oh, the joys of early attempts!

I see your patches for this chipset have now arrived and I'll test them 
as soon as I get to that box.
Meanwhile I've captured a similar log from another (and actually this 
one is my main concern because it can not be replaced easily):

https://pastebin.com/NVfRcMww

Something is clearly different here, 8259A.pl reports all irqs are edge 
no matter what. BIOS setup only offers some strange "PCI IDE IRQ mode" 
(Edge/Level) and apparently it has no effect anyway.
(A modified version of 8139too works fine though)

Thank you,

Regards,
Nikolai

>   It does PCI interrupt steering, it has the ELCR, but we don't have a PIRQ
> router implemented for it.  I have a datasheet, so this should be fairly
> trivial to do, and hopefully things will then work automagically, no need
> for hacks.
>
>   It's very late tonight here, so let me come back with something tomorrow.
>
>    Maciej
>