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

From: Jianmin Lv
Date: Fri Oct 21 2022 - 22:05:58 EST




On 2022/10/21 下午8:01, Bjorn Helgaas wrote:
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.

Ok, good suggestion, thanks.

Bjorn