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

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

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.