Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Thu, 16 Dec 2021 15:31:21 +0100 | Subject | Re: [PATCH] irqchip/renesas-intc-irqpin: Use platform_get_irq_optional() to get the interrupt |
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Hi Prabhakar,
On Thu, Dec 16, 2021 at 3:23 PM Lad, Prabhakar <prabhakar.csengg@gmail.com> wrote: > On Thu, Dec 16, 2021 at 8:45 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > On Thu, Dec 16, 2021 at 12:45 AM Lad Prabhakar > > <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote: > > > platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static > > > allocation of IRQ resources in DT core code, this causes an issue > > > when using hierarchical interrupt domains using "interrupts" property > > > in the node as this bypassed the hierarchical setup and messed up the > > > irq chaining. > > > > > > In preparation for removal of static setup of IRQ resource from DT core > > > code use platform_get_irq_optional(). > > > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> > > > > > --- a/drivers/irqchip/irq-renesas-intc-irqpin.c > > > +++ b/drivers/irqchip/irq-renesas-intc-irqpin.c > > > > > @@ -418,12 +417,14 @@ static int intc_irqpin_probe(struct platform_device *pdev) > > > > > > /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */ > > > for (k = 0; k < INTC_IRQPIN_MAX; k++) { > > > - irq = platform_get_resource(pdev, IORESOURCE_IRQ, k); > > > - if (!irq) > > > + ret = platform_get_irq_optional(pdev, k); > > > + if (ret == -EPROBE_DEFER) > > > + goto err0; > > > + if (ret < 0) > > > break; > > > > Shouldn't all errors be considered fatal, except for -ENXIO (no > > interrupt)? > > > Initial behavior of this driver was even if one > platform_get_resource() succeeded the probe continued further, this is
Indeed, the loop obtained all interrupts present, until no more are to found. In the old logic, it would return a NULL resource for the first non-existing one. In the new logic, it would return -ENXIO. Hence you need to check for -ENXIO in the loop, to distinguish "no more interrupts" from actual errors.
> the same behavior which I wanted to keep with this code while using > platform_get_irq_optional(). But as you pointed out I'll change it to below: > > + ret = platform_get_irq(pdev, k); > + if (ret < 0) > + goto err0; > > We bail out any error case and will also drop the check for (nirqs < 1).
I think that check should stay: there should be at least one interrupt.
> > > p->irq[k].p = p; > > > - p->irq[k].requested_irq = irq->start; > > > + p->irq[k].requested_irq = ret; > > > } > > > > > > nirqs = k;
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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