Re: [Qemu-devel] [PATCH] fsl-imx6: Swap Ethernet interrupt defines

[Bill Paul]

Of all the gin joints in all the towns in all the world, Guenter Roeck had to 
walk into mine at 13:38 on Friday 09 March 2018 and say:

[...]
> > > > Do I have that right?
> > > 
> > > Pretty much.
> > 
> > There may be a 4th option.
> > 
> > Since older kernels work because they were looking at vector 151, you
> > could patch the imx_fec.c module so that when it signals an event for
> > vector 150, it also signals vector 151 too. This would keep newer
> > versions of QEMU "bug- compatible" with older versions while also fixing
> > support for newer Linux kernels and other guests (e.g. VxWorks) that
> > follow the hardware spec correctly.
> > 
> > I think this would require only a small modification to this function:
> > 
> > static void imx_eth_update(IMXFECState *s)
> > {
> > 
> >     if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] & ENET_INT_TS_TIMER) {
> >     
> >         qemu_set_irq(s->irq[1], 1);
> >     
> >     } else {
> >     
> >         qemu_set_irq(s->irq[1], 0);
> >     
> >     }
> >     
> >     if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] & ENET_INT_MAC) {
> >     
> >         qemu_set_irq(s->irq[0], 1);
> >     
> >     } else {
> >     
> >         qemu_set_irq(s->irq[0], 0);
> >     
> >     }
> > 
> > }
> > 
> > (For ENET_INT_MAC events, just signal both s->irq[0] and s->irq[1]).
> 
> Now this is an excellent idea.
> 
> > This of course means signaling spurious events on vector 151, but you're
> > doing that now anyway. :)
> 
> Actually, it doesn't. It looks like the first interrupt is handled,
> resetting the interrupt status, and the second interrupt is never even
> executed. I tested this with all kernel releases back to v3.16.

I just did a quick test with your patch and I can confirm that VxWorks 7 also 
works correctly.

-Bill

> I'll send out patch v2 with this change and let Peter decide which version
> to apply.
> 
> Thanks,
> Guenter
-- 
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-Bill Paul            (510) 749-2329 | Senior Member of Technical Staff,
                 address@hidden | Master of Unix-Fu - Wind River Systems
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   "I put a dollar in a change machine. Nothing changed." - George Carlin
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