Re: [PATCH v3 2/2] genirq: fasteoi supports resend on concurrent invoke

[Marc Zyngier]

On 2023-06-07 13:21, Gowans, James wrote:
> On Tue, 2023-06-06 at 18:05 +0100, Marc Zyngier wrote:
> > On Mon, 05 Jun 2023 16:57:23 +0100,
> > James Gowans <jgowans@xxxxxxxxxx> wrote:
> > > ... and enable that functionality for GIC-v3 only.
> >
> > nit: drop the multi-line subject.
>
> Would you prefer two commits - one to introduce the functionality and 
> one
> to enable it for GIC-v3?

I'd prefer that. It is in general better to decouple driver stuff from
core code.

> > diff --git a/include/linux/irq.h b/include/linux/irq.h
> > > index b1b28affb32a..b76cc90faebd 100644
> > > --- a/include/linux/irq.h
> > > +++ b/include/linux/irq.h
> > > @@ -223,6 +223,8 @@ struct irq_data {
> > >   *                             irq_chip::irq_set_affinity() when deactivated.
> > >   * IRQD_IRQ_ENABLED_ON_SUSPEND       - Interrupt is enabled on suspend by irq pm if
> > >   *                             irqchip have flag IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND set.
> > > + * RQD_RESEND_WHEN_IN_PROGRESS       - Interrupt may fire when already in progress in which
> > > + *                             case it must be resent at the next available opportunity.
> > >   */
> > >  enum {
> > >       IRQD_TRIGGER_MASK               = 0xf,
> > > @@ -249,6 +251,7 @@ enum {
> > >       IRQD_HANDLE_ENFORCE_IRQCTX      = (1 << 28),
> > >       IRQD_AFFINITY_ON_ACTIVATE       = (1 << 29),
> > >       IRQD_IRQ_ENABLED_ON_SUSPEND     = (1 << 30),
> > > +     IRQD_RESEND_WHEN_IN_PROGRESS    = (1 << 31),
> >
> > Make this unsigned, as it otherwise has the potential to sign-extend
> > and lead to "fun to debug" issues.
>
> Ack, doing this change:
>
> @@ -251,7 +251,7 @@ enum {
>         IRQD_HANDLE_ENFORCE_IRQCTX      = (1 << 28),
>         IRQD_AFFINITY_ON_ACTIVATE       = (1 << 29),
>         IRQD_IRQ_ENABLED_ON_SUSPEND     = (1 << 30),
> -       IRQD_RESEND_WHEN_IN_PROGRESS    = (1 << 31),
> +       IRQD_RESEND_WHEN_IN_PROGRESS    = (1U << 31),
>  };
>
> (looks a bit odd having only this one unsigned though...)

Eventually, someone will bite the bullet and use BIT() everywhere.

Thanks,

        M.
--
Jazz is not dead. It just smells funny...