Re: [PATCH 6/8] q800: route SONIC on-board Ethernet IRQ via nubus IRQ 9 in classic mode

[Mark Cave-Ayland]

On 16/10/2021 19:08, Laurent Vivier wrote:

> Le 13/10/2021 à 23:21, Mark Cave-Ayland a écrit :
> > When the hardware is operating in classic mode the SONIC on-board Ethernet IRQ 
> > is
> > routed to nubus IRQ 9 instead of directly to the CPU at level 3. This does not
> > affect the framebuffer which although it exists in slot 9, has its own
> > dedicated IRQ on the Quadra 800 hardware.
> >
> > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> > ---
> >   hw/m68k/q800.c | 57 ++++++++++++++++++++++++++++++++++++++++----------
> >   1 file changed, 46 insertions(+), 11 deletions(-)
> >
> > diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
> > index 0093872d89..d55e6a7541 100644
> > --- a/hw/m68k/q800.c
> > +++ b/hw/m68k/q800.c
> > @@ -101,6 +101,7 @@ struct GLUEState {
> >       M68kCPU *cpu;
> >       uint8_t ipr;
> >       uint8_t auxmode;
> > +    qemu_irq irqs[1];
> >   };
> >   
> >   #define GLUE_IRQ_IN_VIA1       0
> > @@ -108,27 +109,50 @@ struct GLUEState {
> >   #define GLUE_IRQ_IN_SONIC      2
> >   #define GLUE_IRQ_IN_ESCC       3
> >   
> > +#define GLUE_IRQ_NUBUS_9       0
> > +
> >   static void GLUE_set_irq(void *opaque, int irq, int level)
> >   {
> >       GLUEState *s = opaque;
> >       int i;
> >   
> > -    switch (irq) {
> > -    case GLUE_IRQ_IN_VIA1:
> > -        irq = 5;
> > -        break;
> > +    switch (s->auxmode) {
> > +    case 0:
>
> why don't you use "if () {} else {}" rather than "switch() { case 0: ; case 1: 
> }" ?
> (I don't think we need to manage a "default:" case.)

Sure, I can do that: I used the switch()/default originally to make sure the irq 
wasn't being set to an unexpected value.

I've also just spotted that the comment in this patch is incorrect:

    /*
     * Since the framebuffer in slot 0x9 uses a separate IRQ, wire the unused
     * IRQ via GLUE for use by SONIC Ethernet in A/UX mode
     */

This should be classic mode, of course.


ATB,

Mark.