Re: [PATCH v2 3/5] irqchip: Allow QCOM_PDC to be loadable as a permanent module

[Marc Zyngier]

On Sat, 27 Jun 2020 02:34:25 +0100,
John Stultz <john.stultz@xxxxxxxxxx> wrote:
> 
> On Fri, Jun 26, 2020 at 12:42 AM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
> >
> > Quoting John Stultz (2020-06-24 17:10:37)
> > > diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
> > > index 6ae9e1f0819d..3fee8b655da1 100644
> > > --- a/drivers/irqchip/qcom-pdc.c
> > > +++ b/drivers/irqchip/qcom-pdc.c
> > > @@ -430,4 +432,33 @@ static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
> > >         return ret;
> > >  }
> > >
> > > +#ifdef MODULE
> > > +static int qcom_pdc_probe(struct platform_device *pdev)
> > > +{
> > > +       struct device_node *np = pdev->dev.of_node;
> > > +       struct device_node *parent = of_irq_find_parent(np);
> > > +
> > > +       return qcom_pdc_init(np, parent);
> > > +}
> > > +
> > > +static const struct of_device_id qcom_pdc_match_table[] = {
> > > +       { .compatible = "qcom,pdc" },
> > > +       {}
> > > +};
> > > +MODULE_DEVICE_TABLE(of, qcom_pdc_match_table);
> > > +
> > > +static struct platform_driver qcom_pdc_driver = {
> > > +       .probe = qcom_pdc_probe,
> > > +       .driver = {
> > > +               .name = "qcom-pdc",
> > > +               .of_match_table = qcom_pdc_match_table,
> > > +               .suppress_bind_attrs = true,
> > > +       },
> > > +};
> > > +module_platform_driver(qcom_pdc_driver);
> > > +#else
> > >  IRQCHIP_DECLARE(qcom_pdc, "qcom,pdc", qcom_pdc_init);
> >
> > Is there any reason to use IRQCHIP_DECLARE if this can work as a
> > platform device driver?
> >
> 
> Hey! Thanks so much for the review!
> 
> Mostly it was done this way to minimize the change in the non-module
> case. But if you'd rather avoid the #ifdefery I'll respin it without.

That would certainly be my own preference. In general, IRQCHIP_DECLARE
and platform drivers should be mutually exclusive in the same driver:
if you can delay the probing and have it as a proper platform device,
then this should be the one true way.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.