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References: <20211215234946.6494-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
In-Reply-To: <20211215234946.6494-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Sat, 25 Dec 2021 18:45:33 +0200
Message-ID: <CAHp75VfGwQ7G2b39GO4tN=sxQoiahO2uudy25ALxEkrNcP9eVw@mail.gmail.com>
Subject: Re: [PATCH] irqchip/renesas-irqc: Use platform_get_irq_optional() to
 get the interrupt
To:     Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Prabhakar <prabhakar.csengg@gmail.com>
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On Thu, Dec 16, 2021 at 9:52 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().


> +               ret = platform_get_irq_optional(pdev, k);
> +               if (ret == -EPROBE_DEFER)
> +                       goto err_runtime_pm_disable;
> +               if (ret < 0)
>                         break;

The best approach is

ret = platform_get_irq_optional(...);
if (ret < 0 && ret != -ENXIO)
  return ret;
if (ret > 0)
  ...we got it...

It will allow the future API fix of platform_get_irq_optional() to be
really optional.


--
With Best Regards,
Andy Shevchenko