Re: [PATCH 1/2] thermal/drivers/rcar_gen3: Handle -ENXIO from optional IRQ lookup

Hi Geert,

Thank you for your feedback.

> >                 irq = platform_get_irq_optional(pdev, i);
> > -               if (irq < 0)
> > +               if (irq < 0 && irq != -ENXIO)
> >                         return irq;
> >
>
> So the code may continue using -ENXIO as an interrupt number (and fail)?
>

Yes, you are right. We should probably handle it similarly to:
https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/thermal/renesas/rcar_thermal.c#L422
and only assign the IRQ when the return value is positive:
if (ret > 0)
   irq = ret;

> Why is this change needed at all?
> The caller of rcar_gen3_thermal_request_irqs() knows how to handle
> failures, as IRQs are optional.
>

Regarding the caller, I only found rcar_gen3_thermal_request_irqs()
being called here:
https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/thermal/renesas/rcar_gen3_thermal.c#L530
It does not appear to handle the error return there, so I don't think
the caller currently handles these failures explicitly.

Best regards,
Phuc