Re: [PATCH v2 3/5] gpio: msc313: MStar MSC313 GPIO driver

[Marc Zyngier]

On 2020-11-10 14:02, Linus Walleij wrote:
> On Thu, Nov 5, 2020 at 4:43 PM Marc Zyngier <maz@xxxxxxxxxx> wrote:
> > On 2020-11-05 15:23, Daniel Palmer wrote:
> > > On Thu, 5 Nov 2020 at 21:08, Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> > > >  I see that msc313_gpio_irqchip doesn't have a
> > >> .irq_set_affinity callback. Is this system UP only?
> > >
> > > What is in mainline right now is UP only but there are chips with a
> > > second cortex A7 that I have working in my tree.
> > > So I will add that in for v3 if I can work out what I should actually
> > > do there. :)
> >
> > Probably nothing more than setting the callback to
> > irq_chip_set_affinity_parent,
>
> Hm, is this something all GPIO irqchips used on SMP systems
> should be doing? Or just hierarchical ones?

Probably only the hierarchical ones. I'd expect the non-hierarchical
GPIOs to be muxed behind a single interrupt, which makes it impossible
to move a single GPIO around, and moving the mux interrupt would break
userspace's expectations that interrupts move independently of each 
others.

Thanks,

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