Re: [PATCH 1/8] mac_via: update comment for VIA1B_vMystery bit

[Laurent Vivier]

Le 13/10/2021 à 23:21, Mark Cave-Ayland a écrit :
> According to both Linux and NetBSD, port B bit 6 is used on the Quadra 800 to
> configure the GLUE logic in A/UX mode. Whilst the name VIA1B_vMystery isn't
> particularly descriptive, the patch leaves this to ensure that the constants
> in mac_via.c remain in sync with Linux's mac_via.h.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hw/misc/mac_via.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
> index 993bac017d..7a53a8b4c0 100644
> --- a/hw/misc/mac_via.c
> +++ b/hw/misc/mac_via.c
> @@ -130,6 +130,10 @@
>                                  * On SE/30, vertical sync interrupt enable.
>                                  * 0=enabled. This vSync interrupt shows up
>                                  * as a slot $E interrupt.
> +                                * On Quadra 800 this bit toggles A/UX mode 
> which
> +                                * configures the glue logic to deliver some 
> IRQs
> +                                * at different levels compared to a classic
> +                                * Mac.
>                                  */
>  #define VIA1B_vADBS2   0x20    /* ADB state input bit 1 (unused on IIfx) */
>  #define VIA1B_vADBS1   0x10    /* ADB state input bit 0 (unused on IIfx) */
> 

I'm not sure we need to keep in sync a word that neither used by linux or qemu 
(for now).

Perhaps you can put a word from where it is (NetBSD)?

It seems it's supported by all Quadra, not only Quadra 800 (see NetBSD comment 
in mac68k/machdep.c

Anyway:

Reviewed-by: Laurent Vivier <laurent@vivier.Eu>