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

On Friday 23 July 2021 15:59:12 Kunihiko Hayashi wrote:

Hi Pali,

On 2021/07/23 2:26, Pali Rohár wrote:

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On Friday 23 July 2021 01:54:10 Kunihiko Hayashi wrote:

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On 2021/07/18 9:51, Pali Rohar wrote:

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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@kernel.org/ (local)

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@kernel.org/ (local)

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.

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.

quoted

There is no need to modify DTS. And also no need to use complicated
logic for finding registered virq number via pcie_port_service_get_irq()
and uniphier_pcie_port_get_irq() functions.

I see.
GIC interrupt for MSI is handled by the MSI domain by pcie-designware-host.c.
My concern is how to trigger PME/AER event with another IRQ domain.

Thank you,

---
Best Regards
Kunihiko Hayashi

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