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

[Prabhakar Mahadev Lad]

Hi Andy,

Thank you for the review.

> -----Original Message-----
> From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Sent: 25 December 2021 17:49
> To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>; Ray Jui <rjui@xxxxxxxxxxxx>; Scott Branden
> <sbranden@xxxxxxxxxxxx>; bcm-kernel-feedback-list <bcm-kernel-feedback-list@xxxxxxxxxxxx>; Nicolas
> Saenz Julienne <nsaenz@xxxxxxxxxx>; Chris Brandt <Chris.Brandt@xxxxxxxxxxx>; Wolfram Sang
> <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; linux-i2c <linux-i2c@xxxxxxxxxxxxxxx>; linux-rpi-kernel <linux-
> rpi-kernel@xxxxxxxxxxxxxxxxxxx>; linux-arm Mailing List <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; Linux-
> Renesas <linux-renesas-soc@xxxxxxxxxxxxxxx>; Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>;
> Prabhakarprabhakar.csengg@xxxxxxxxx
> 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@xxxxxxxxxxxxxx> 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