Re: [PATCH 07/11] of/irq: Export of_irq_count to drivers

Rob Herring
2021-09-27T20:11:34Z

On Mon, Sep 27, 2021 at 2:49 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
>
> On 9/27/21 12:43 PM, Rob Herring wrote:
> > On Mon, Sep 27, 2021 at 2:28 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
> >>
> >> On 9/27/21 12:08 PM, Rob Herring wrote:
> >>> On Fri, Sep 24, 2021 at 12:07 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
> >>>>
> >>>> In order to build drivers/irqchip/irq-bcm7120-l2.c as a module, we will
> >>>> need to have of_irq_count() exported to modules.
> >>>>
> >>>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> >>>> ---
> >>>> drivers/of/irq.c | 1 +
> >>>> 1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> >>>> index 352e14b007e7..949b9d1f8729 100644
> >>>> --- a/drivers/of/irq.c
> >>>> +++ b/drivers/of/irq.c
> >>>> @@ -440,6 +440,7 @@ int of_irq_count(struct device_node *dev)
> >>>>
> >>>> return nr;
> >>>> }
> >>>> +EXPORT_SYMBOL_GPL(of_irq_count);
> >>>
> >>> Please convert to use platform_irq_count() instead.
> >>
> >> That requires a platform_device to be passed to platform_irq_count(),
> >> will that work even when the drivers remain built into the kernel and
> >> get initialized early on?
> >
> > No, does your irqchip using this do both? Looks to me like it is
> > always a platform_device.
>
> On ARM/ARM64 not using GKI as well as MIPS, we would want the module to
> be built into the kernel image, however when using GKI that driver would
> become a module. How do you suggest reconciling both usages?

What's there to resolve? Every driver that works as a module can be
built-in. Is there something special about irqchip drivers?

The only issue I see here is platform_irqchip_probe() doesn't pass the
platform_device pointer to the irq_init_cb function. There's 3 ways to
fix that. Add a platform_device pointer to the init hook. That's a
global change though. That's the right thing to do IMO. Or you can use
of_find_device_by_node(). That's fairly expensive, but easy and
isolated. You could also set device_node.data pointer to the
platform_device, but ideally I'd like to get rid of that pointer as
it's hardly used.

Rob