Re: [PATCH 2/4] irqchip/loongson-eiointc: Add suspend/resume support

[Huacai Chen]

Hi, Marc,

On Wed, Oct 19, 2022 at 3:23 PM Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On Mon, 17 Oct 2022 04:39:02 +0100,
> Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
> >
> > Add suspend/resume support for EIOINTC irqchip, which is needed for
> > upcoming suspend/hibernation.
> >
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> >  drivers/irqchip/irq-loongson-eiointc.c | 31 ++++++++++++++++++++++++++
> >  1 file changed, 31 insertions(+)
> >
> > diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
> > index 16e9af8d8b1e..c68f8de3ae09 100644
> > --- a/drivers/irqchip/irq-loongson-eiointc.c
> > +++ b/drivers/irqchip/irq-loongson-eiointc.c
> > @@ -17,6 +17,7 @@
> >  #include <linux/of_address.h>
> >  #include <linux/of_irq.h>
> >  #include <linux/of_platform.h>
> > +#include <linux/syscore_ops.h>
> >
> >  #define EIOINTC_REG_NODEMAP  0x14a0
> >  #define EIOINTC_REG_IPMAP    0x14c0
> > @@ -301,6 +302,35 @@ static struct irq_domain *acpi_get_vec_parent(int node, struct acpi_vector_group
> >       return NULL;
> >  }
> >
> > +static int eiointc_suspend(void)
> > +{
> > +     return 0;
> > +}
> > +
> > +static void eiointc_resume(void)
> > +{
> > +     int i, j;
> > +     struct irq_desc *desc;
> > +     struct irq_data *irq_data;
> > +
> > +     eiointc_router_init(0);
> > +
> > +     for (i = 0; i < nr_pics; i++) {
> > +             for (j = 0; j < VEC_COUNT; j++) {
> > +                     desc = irq_resolve_mapping(eiointc_priv[i]->eiointc_domain, j);
> > +                     if (desc && desc->handle_irq && desc->handle_irq != handle_bad_irq) {
> > +                             irq_data = &desc->irq_data;
> > +                             eiointc_set_irq_affinity(irq_data, irq_data->common->affinity, 0);
>
> Changing the affinity without holding the irq_desc lock? What makes
> this safe?
Yes, holding the lock is needed, thanks.

Huacai
>
>         M.
>
> --
> Without deviation from the norm, progress is not possible.