Re: [PATCH v2 2/4] hw/char/pl011: implement a reset method

[Evgeny Iakovlev <eiakovlev@linux.microsoft.com>]

On 1/19/2023 14:27, Peter Maydell wrote:
> On Tue, 17 Jan 2023 at 22:05, Evgeny Iakovlev
> <eiakovlev@linux.microsoft.com> wrote:
>> PL011 currently lacks a reset method. Implement it.
>>
>> Signed-off-by: Evgeny Iakovlev <eiakovlev@linux.microsoft.com>
>> ---
>>   hw/char/pl011.c | 31 ++++++++++++++++++++++++++-----
>>   1 file changed, 26 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/char/pl011.c b/hw/char/pl011.c
>> index 329cc6926d..404d52a3b8 100644
>> --- a/hw/char/pl011.c
>> +++ b/hw/char/pl011.c
>> @@ -397,11 +397,6 @@ static void pl011_init(Object *obj)
>>       s->clk = qdev_init_clock_in(DEVICE(obj), "clk", pl011_clock_update, s,
>>                                   ClockUpdate);
>>
>> -    s->read_trigger = 1;
>> -    s->ifl = 0x12;
>> -    s->cr = 0x300;
>> -    s->flags = 0x90;
>> -
>>       s->id = pl011_id_arm;
>>   }
>>
>> @@ -413,11 +408,37 @@ static void pl011_realize(DeviceState *dev, Error **errp)
>>                                pl011_event, NULL, s, NULL, true);
>>   }
>>
>> +static void pl011_reset(DeviceState *dev)
>> +{
>> +    PL011State *s = PL011(dev);
>> +    int i;
>> +
>> +    s->lcr = 0;
>> +    s->rsr = 0;
>> +    s->dmacr = 0;
>> +    s->int_enabled = 0;
>> +    s->int_level = 0;
>> +    s->ilpr = 0;
>> +    s->ibrd = 0;
>> +    s->fbrd = 0;
>> +    s->read_pos = 0;
>> +    s->read_count = 0;
>> +    s->read_trigger = 1;
>> +    s->ifl = 0x12;
>> +    s->cr = 0x300;
>> +    s->flags = 0x90;
>> +
>> +    for (i = 0; i < ARRAY_SIZE(s->irq); i++) {
>> +        qemu_irq_lower(s->irq[i]);
>> +    }
> Reset should never touch outbound qemu_irq lines.
> (The other end of the line will also reset and will end
> up in the correct "as if the input is 0" state.)


Really? I saw this reset happening on other devices in hw/char (don't 
remember which ones specifically), so i though it is needed.


>
> Otherwise
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> thanks
> -- PMM