Re: [Qemu-devel] [PATCH] fix disabling interrupts in sun4u

[Artyom Tarasenko]

On Sat, Jul 30, 2011 at 11:09 AM, Blue Swirl <address@hidden> wrote:
> On Mon, Jul 25, 2011 at 8:22 PM, Artyom Tarasenko <address@hidden> wrote:
>> clear interrupt request if the interrupt priority < CPU pil
>> clear hardware interrupt request if interrupts are disabled
>>
>> Signed-off-by: Artyom Tarasenko <address@hidden>
>> ---
>>  hw/sun4u.c |    6 ++++--
>>  1 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/sun4u.c b/hw/sun4u.c
>> index d7dcaf0..7f95aeb 100644
>> --- a/hw/sun4u.c
>> +++ b/hw/sun4u.c
>> @@ -255,7 +255,7 @@ void cpu_check_irqs(CPUState *env)
>>         pil |= 1 << 14;
>>     }
>>
>> -    if (!pil) {
>> +    if (pil < (2 << env->psrpil)){
>
> Sorry, I don't understand the patch. Where is this '2' coming from?

We shouldn't interrupt at levels <= psrpil. The bit corresponding to
psrpil is (1<< psrpil),
the next bit is (2 << psrpil).

>
>>         if (env->interrupt_request & CPU_INTERRUPT_HARD) {
>>             CPUIRQ_DPRINTF("Reset CPU IRQ (current interrupt %x)\n",
>>                            env->interrupt_index);
>> @@ -287,10 +287,12 @@ void cpu_check_irqs(CPUState *env)
>>                 break;
>>             }
>>         }
>> -    } else {
>> +    } else if (env->interrupt_request & CPU_INTERRUPT_HARD) {
>>         CPUIRQ_DPRINTF("Interrupts disabled, pil=%08x pil_in=%08x 
>> softint=%08x "
>>                        "current interrupt %x\n",
>>                        pil, env->pil_in, env->softint, env->interrupt_index);
>> +        env->interrupt_index = 0;
>> +        cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
>
> Why reset the index? The idea is that the interrupt is left pending a
> change to PIL etc.

But it is kept in  env->pil_in and env->softint . Am I missing some
scenario where it's not enough?

>>     }
>>  }
>>
>> --
>> 1.7.3.4
>>
>>
>



-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/