Re: [Qemu-devel] [Qemu-ppc] [RESEND][PATCH] booke timers

[Fabien Chouteau <chouteau@adacore.com>]

On 12/09/2011 19:23, Scott Wood wrote:
> On 09/09/2011 09:58 AM, Alexander Graf wrote:
>> On 09.09.2011, at 16:22, Fabien Chouteau wrote:
>>> if the interrupt is already set and you clear TCR.DIE, the interrupt has to
>>> remain set. The only way to unset an interrupt is to clear the corresponding
>>> bit in TSR (currently in store_booke_tsr).
>>
>> Are you sure? I see several things in the 2.06 spec:
> [snip]
>> To me that sounds as if the decrementer interrupt gets injected only
>> when TSR.DIS=1, TCR.DIE=1 and MSR.EE=1. Unsetting any of these bits
>> stops the interrupt from being delivered.
>>
>> Scott, can you please check up with the hardware guys if this is correct?
>
> This is how I've always understood it to work (assuming the interrupt
> hasn't already been delivered, of course).  Fabien, do you have real
> hardware that you see behave the way you describe?
>

No I don't, it was just my understanding of Book-E documentation. I've tried
your solution (below) with VxWorks, and it works like a charm.

static void booke_update_irq(CPUState *env)
{
    ppc_set_irq(env, PPC_INTERRUPT_DECR,
                (env->spr[SPR_BOOKE_TSR] & TSR_DIS
                 && env->spr[SPR_BOOKE_TCR] & TCR_DIE));

    ppc_set_irq(env, PPC_INTERRUPT_WDT,
                (env->spr[SPR_BOOKE_TSR] & TSR_WIS
                 && env->spr[SPR_BOOKE_TCR] & TCR_WIE));

    ppc_set_irq(env, PPC_INTERRUPT_FIT,
                (env->spr[SPR_BOOKE_TSR] & TSR_FIS
                 && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
}

Regards,

-- 
Fabien Chouteau