Re: [PATCH v8 3/3] PCI: uniphier: Add misc interrupt handler to invoke PME and AER

[Kunihiko Hayashi]

Hi Pali,

On 2021/07/23 17:37, Pali Rohár wrote:
> On Friday 23 July 2021 15:59:12 Kunihiko Hayashi wrote:
> > Hi Pali,
> >
> > On 2021/07/23 2:26, Pali Rohár wrote:
> > > On Friday 23 July 2021 01:54:10 Kunihiko Hayashi wrote:
> > > > On 2021/07/18 9:51, Pali Rohar wrote:
> > > > > > > IMO this should be modelled with a separate IRQ domain and chip for
> > > > > > > the root port (yes this implies describing the root port in the dts
> > > > > > > file with a separate msi-parent).
> > > > > > >
> > > > > > > This series as it stands is a kludge.
> > > > > >
> > > > > > I see. However I need some time to consider the way to separate IRQ domain.
> > > > > > Is there any idea or example to handle PME/AER with IRQ domain?
> > > > >
> > > > > Seems that you are dealing with very similar issues as me with aardvark
> > > > > driver.
> > > > >
> > > > > As an inspiration look at my aardvark patch which setup separate IRQ
> > > > > domain for PME, AER and HP interrupts:
> > > > > https://lore.kernel.org/linux-pci/20210506153153.30454-32-pali@xxxxxxxxxx/
> > > > >
> > > > > Thanks to custom driver map_irq function, it is not needed to describe
> > > > > root port with separate msi-parent in DTS.
> > > >
> > > > I need to understand your solution, though, this might be the same situation as my driver.
> > >
> > > I think it is very very similar as aardvark also returns zero as hw irq
> > > number (and it is not possible to change it).
> > >
> > > So simple solution for you is also to register separate IRQ domain for
> > > Root Port Bridge and then re-trigger interrupt with number 0 (which you
> > > wrote that is default) as:
> > >
> > >       virq = irq_find_mapping(priv->irq_domain, 0);
> > >       generic_handle_irq(virq);
> > >
> > > in your uniphier_pcie_misc_isr() function.
> >
> > I'm not sure "register separate IRQ domain for Root Port Bridge".
> > Do you mean that your suggestion is to create new IRQ domain, and add this domain to root port?
>
> Yes.
>
> > Or could you show me something example?
>
> I have already sent link to patch above which it implements for
> pci-aardvark.c driver.
>
> https://lore.kernel.org/linux-pci/20210506153153.30454-32-pali@xxxxxxxxxx/

Thank you for the example.

> In device prove callback register domain by irq_domain_add_linear().
> In bridge map_irq() callback use irq_create_mapping() for Root Port
> device (and otherwise default of_irq_parse_and_map_pci()). And in
> uniphier_pcie_misc_isr() retrigger interrupt into new domain.

I understand it late.
The main point is to replace bridge->map_irq() with private own map_irq().

> > The re-trigger part is the same method as v5 patch I wrote.
>
> Just you need to specify that new/private IRQ domain into
> irq_find_mapping() call.

I'll try to replace the events with new IRQ domain.

Thank you,

---
Best Regards
Kunihiko Hayashi