Re: [PATCH v5 08/17] ACPI: pci_link: Clear the dependencies after probe

Andy Shevchenko
2024-05-02T09:25:46Z

On Wed, May 01, 2024 at 11:56:15AM -0500, Bjorn Helgaas wrote:
> On Wed, May 01, 2024 at 05:47:33PM +0530, Sunil V L wrote:
> > RISC-V platforms need to use dependencies between PCI host bridge, Link
> > devices and the interrupt controllers to ensure probe order. The
> > dependency is like below.
> >
> > Interrupt controller <-- Link Device <-- PCI Host bridge.
> >
> > If there is no dependency added between Link device and PCI Host Bridge,
> > then the PCI end points can get probed prior to link device, unable to
> > get mapping for INTx.
> >
> > So, add the link device's HID to dependency honor list and also clear it
> > after its probe.
> >
> > Since this is required only for architectures like RISC-V, enable this
> > code under a new config option and set this only in RISC-V.

...

> > + if (IS_ENABLED(CONFIG_ARCH_ACPI_DEFERRED_GSI))
> > + acpi_dev_clear_dependencies(device);
>
> This is really a question for Rafael, but it doesn't seem right that
> this completely depends on a config option.

+1 here, fells like a hack and looks like a hack.

> Is there a reason this wouldn't work for all architectures, i.e., what
> would happen if you just called acpi_dev_clear_dependencies()
> unconditionally?

--
With Best Regards,
Andy Shevchenko