Re: [RFC PATCH v4 2/5] irqchip: Add RZ/G2L IA55 Interrupt Controller driver

Marc Zyngier
2022-03-18T17:44:36Z

On Fri, 18 Mar 2022 14:59:41 +0000,
"Lad, Prabhakar" <prabhakar.csengg@gmail.com> wrote:
>
> Hi Marc,
>
> Thank you for the review.
>
> On Thu, Mar 17, 2022 at 4:13 PM Marc Zyngier <maz@kernel.org> wrote:
> >
> > On Thu, 17 Mar 2022 01:24:01 +0000,
> > Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> > >
> > > +static struct irq_chip irqc_chip = {
> > > + .name = "rzg2l-irqc",
> > > + .irq_eoi = rzg2l_irqc_eoi,
> > > + .irq_mask = irq_chip_mask_parent,
> > > + .irq_unmask = irq_chip_unmask_parent,
> > > + .irq_disable = rzg2l_irqc_irq_disable,
> > > + .irq_enable = rzg2l_irqc_irq_enable,
> >
> > So this looks a bit odd. irq_mask only calls the parent and does nothing
> > locally, while irq_disable does something locally and calls into the
> > parent. If the parent is a GIC, this is turned into a mask (GIC has no
> > notion of disabled).
> >
> My understanding for enable callback is one time call during irq setup
> and for the disable callback it will be called during irq shutdown.
> During enable/disable callback we config the required registers.
> For mask callback this will be called when an interrupt occurs and for
> unmask we want to re-enable the interrupt. Since there are no specific
> registers to mask/unmask on RZ/G2L the callbacks point to
> irq_chip_mask_parent/irq_chip_unmask_parent.
>
> I could move all the code from enable/disable callbacks to mask/unmask
> callbacks and drop setting irq_enable/irq_disable completely. Please
> let me know what should be the correct approach.

I'm OK with your current setup, but I just wanted to check that this
was your understanding as well.

M.

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