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

[Evgeny Iakovlev]

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