Re: [PATCH V4 1/4] ACPI / PCI: fix LPIC IRQ model default PCI IRQ polarity

[Bjorn Helgaas]

On Fri, Oct 21, 2022 at 09:58:57AM +0800, Jianmin Lv wrote:
> On 2022/10/21 上午12:47, Bjorn Helgaas wrote:
> > On Thu, Oct 20, 2022 at 04:22:02PM +0800, Jianmin Lv wrote:
> > > On LoongArch ACPI based systems, the PCI devices (e.g. sata
> > > controlers and PCI-to-to PCI bridge controlers) existed in
> > > Loongson chipsets output high-level interrupt signal to the
> > > interrupt controller they connected to,

> > The point is that one should be able to write this code from a spec,
> > without having to empirically discover the interrupt polarity.  What
> > spec tells you about using ACTIVE_HIGH here?
> > 
> Yes, no mentions for the inverter in ACPI spec, the description about
> device interrupt type can be found in Loongson chipset manual:
> 
> https://github.com/loongson/LoongArch-Documentation/blob/main/docs/Loongson-7A1000-usermanual-EN/interrupt-controller/device-interrupt-types.adoc

That's the kind of reference I was looking for.  The link to HTML is
convenient in some ways, but since specs evolve over time and URLs are
ephemeral, I think a citation like "Loongson 7A1000 Bridge User Manual
v2.00, sec 5.3" is more likely to be useful far in the future.

Bjorn