Re: PowerBook 5xx instability fix.

[Tetsuya Isaki <isaki%pastel-flower.jp@localhost>]

At Sun, 30 Mar 2025 11:29:38 +1100,
Nat Sloss wrote:
> I've done some more investigating.  It seems it is only unstable
> when using an
> audio kernel.  I believe there is a possibility some of the pages
> at the top
> on memory are being used by the ASC/EASC.
>
> The crashes are easily reproducible as simple as listing a directory
> while
> triggering a console bell.

At Sun, 30 Mar 2025 13:39:47 +1100,
Nat Sloss wrote:
> Is something like this OK?
:
> --- a/sys/arch/mac68k/mac68k/pmap_bootstrap.c   Sat Mar 29 01:43:38
2025 +0000
> +++ b/sys/arch/mac68k/mac68k/pmap_bootstrap.c   Sun Mar 30 13:36:45
2025 +1100
>         maxaddr = high[numranges - 1] - m68k_ptob(1);
> -       high[numranges - 1] -= (m68k_round_page(MSGBUFSIZE) +
m68k_ptob(1));
> +
> +       /*
> +        * Reduce high by an extra 7 pages which seem to be used by
the EASC
> +        * ascaudio(4) on some machines.

The above your messsage says ascaudio has issues.
The next your message says you're not sure what's going on.
It's better to look into it more before modifying pmap.
With typical audio MD drivers, it's unlikely to need pmap
modification (though I'm not sure about mac specific).
---
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>