Re: [PATCH v2 2/2] of: property: Add fw_devlink support for interrupts

[Saravana Kannan <saravanak@google.com>]

On Sun, Feb 14, 2021 at 7:58 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 2/14/21 1:12 PM, Saravana Kannan wrote:
> [ ... ]
> >
> > Can you please give me the following details:
> > * The DTS file for the board (not the SoC).
>
> The devicetree file extracted from the running system is attached.
> Hope it helps.

Hi Guenter,

Thanks for the DTS file and logs. That helps a lot.

Looking at the attachment and this line from the earlier email:
[   14.084606][   T11] pci 0005:01:00.0: probe deferral - wait for
supplier interrupt-controller@0

It's clear the PCI node is waiting on:
        interrupt-controller@0 {
                #address-cells = <0x00>;
                device_type = "PowerPC-Interrupt-Source-Controller";
                compatible = "ibm,opal-xive-vc\0IBM,opal-xics";
                #interrupt-cells = <0x02>;
                reg = <0x00 0x00 0x00 0x00>;
                phandle = <0x804b>;
                interrupt-controller;
        };

If I grep for "ibm,opal-xive-vc", I see only one instance of it in the
code. And that eventually ends up getting called like this:
irq_find_matching_fwspec() -> xive_irq_domain_match() -> xive_native_match()

static bool xive_native_match(struct device_node *node)
{
        return of_device_is_compatible(node, "ibm,opal-xive-vc");
}

However, when the IRQ domain are first registered, in xive_init_host()
the "np" passed in is NOT the same node that xive_native_match() would
match.
static void __init xive_init_host(struct device_node *np)
{
        xive_irq_domain = irq_domain_add_nomap(np, XIVE_MAX_IRQ,
                                               &xive_irq_domain_ops, NULL);
        if (WARN_ON(xive_irq_domain == NULL))
                return;
        irq_set_default_host(xive_irq_domain);
}

Instead, the "np" here is:
        interrupt-controller@6030203180000 {
                ibm,xive-provision-page-size = <0x10000>;
                ibm,xive-eq-sizes = <0x0c 0x10 0x15 0x18>;
                single-escalation-support;
                ibm,xive-provision-chips = <0x00>;
                ibm,xive-#priorities = <0x08>;
                compatible = "ibm,opal-xive-pe\0ibm,opal-intc";
                reg = <0x60302 0x3180000 0x00 0x10000 0x60302
0x3190000 0x00 0x10000 0x60302 0x31a0000 0x00 0x10000 0x60302
0x31b0000 0x00 0x10000>;
                phandle = <0x8051>;
        };

There are many ways to fix this, but I first want to make sure this is
a valid way to register irqdomains before trying to fix it. I just
find it weird that the node that's registered is unrelated (not a
parent/child) of the node that matches.

Marc,

Is this a valid way to register irqdomains? Just registering
interrupt-controller@6030203180000 DT node where there are multiple
interrupt controllers?

Thanks,
Saravana