RE: [PATCH v2 2/3] i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt

Prabhakar Mahadev Lad
2021-12-25T23:48:43Z

Hi Andy,

Thank you for the review.

> -----Original Message-----
> From: Andy Shevchenko <andy.shevchenko@gmail.com>
> Sent: 25 December 2021 17:49
> To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>; Ray Jui <rjui@broadcom.com>; Scott Branden
> <sbranden@broadcom.com>; bcm-kernel-feedback-list <bcm-kernel-feedback-list@broadcom.com>; Nicolas
> Saenz Julienne <nsaenz@kernel.org>; Chris Brandt <Chris.Brandt@renesas.com>; Wolfram Sang
> <wsa+renesas@sang-engineering.com>; linux-i2c <linux-i2c@vger.kernel.org>; linux-rpi-kernel <linux-
> rpi-kernel@lists.infradead.org>; linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>; Linux-
> Renesas <linux-renesas-soc@vger.kernel.org>; Linux Kernel Mailing List <linux-kernel@vger.kernel.org>;
> Prabhakarprabhakar.csengg@gmail.com
> Subject: Re: [PATCH v2 2/3] i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt
>
> On Wed, Dec 22, 2021 at 2:41 PM 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 bypasses the hierarchical setup and messes up the irq
> > chaining.
> >
> > In preparation for removal of static setup of IRQ resource from DT
> > core code use platform_get_irq_optional() for DT users only.
>
> ...
>
> > + if (np) {
>
> Same comments as per your other patches, i.e.
> Why is this check here?
>
Because the interrupt resource has range of interrupts in one IRQ resource [0]. Let me know if there is any other alternative way to avoid such case.

> > + int irq;
> > +
> > + while ((irq = platform_get_irq_optional(dev, k)) !=
> > + -ENXIO) {
>
> Consider 0 as no IRQ.
>
OK.

[0] https://elixir.bootlin.com/linux/v5.16-rc6/source/arch/sh/kernel/cpu/sh4a/setup-sh7724.c#L454

Cheers,
Prabhakar

> > + if (irq < 0)
> > + return irq;
> > + ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr,
> > + 0, dev_name(&dev->dev),
> > + pd);
> > if (ret) {
> > - dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
> > + dev_err(&dev->dev, "cannot request IRQ
> > + %d\n", irq);
> > return ret;
> > }
> > + k++;
> > + };
> > + } else {
> > + struct resource *res;
> > + resource_size_t n;
> > +
> > + while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
> > + for (n = res->start; n <= res->end; n++) {
> > + ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
> > + 0, dev_name(&dev->dev), pd);
> > + if (ret) {
> > + dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
> > + return ret;
> > + }
> > + }
> > + k++;
> > }
> > - k++;
> > }
>
> --
> With Best Regards,
> Andy Shevchenko