On Fri, 22 Nov 2013 16:43:35 -0800, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> Currently we get the following kind of errors if we try to use
> interrupt phandles to irqchips that have not yet initialized:
>
> irq: no irq domain found for /ocp/pinmux@48002030 !
> WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184()
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012
> (show_stack+0x14/0x1c)
> (dump_stack+0x6c/0xa0)
> (warn_slowpath_common+0x64/0x84)
> (warn_slowpath_null+0x1c/0x24)
> (of_device_alloc+0x144/0x184)
> (of_platform_device_create_pdata+0x44/0x9c)
> (of_platform_bus_create+0xd0/0x170)
> (of_platform_bus_create+0x12c/0x170)
> (of_platform_populate+0x60/0x98)
> ...
>
> This is because we're wrongly trying to populate resources that are not
> yet available. It's perfectly valid to create irqchips dynamically,
> so let's fix up the issue by populating the interrupt resources based
> on a notifier call instead.
>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>
> ---
>
> Rob & Grant, care to merge this for the -rc if this looks OK to you?
>
> These happen for example when using interrupts-extended for omap
> wake-up interrupts where the irq domain is created by pinctrl-single.c
> at module_init time.
>
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -130,6 +130,56 @@ void of_device_make_bus_id(struct device *dev)
> dev_set_name(dev, "%s.%d", node->name, magic - 1);
> }
>
> +/*
> + * The device interrupts are not necessarily available for all
> + * irqdomains initially so we need to populate them using a
> + * notifier.
> + */
> +static int of_device_resource_notify(struct notifier_block *nb,
> + unsigned long event, void *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct device_node *np = pdev->dev.of_node;
> + struct resource *res = pdev->resource;
> + struct resource *irqr = NULL;
> + int num_irq, i, found = 0;
> +
> + if (event != BUS_NOTIFY_BIND_DRIVER)
> + return 0;
> +
> + if (!np)
> + goto out;
> +
> + num_irq = of_irq_count(np);
> + if (!num_irq)
> + goto out;
> +
> + for (i = 0; i < pdev->num_resources; i++, res++) {
> + if (res->flags != IORESOURCE_IRQ ||
> + res->start != -EPROBE_DEFER ||
> + res->end != -EPROBE_DEFER)
> + continue;
> +
> + if (!irqr)
> + irqr = res;
> + found++;
> + }
> +
> + if (!found)
> + goto out;
> +
> + if (found != num_irq) {
> + dev_WARN(dev, "error populating irq resources: %i != %i\n",
> + found, num_irq);
> + goto out;
> + }
> +
> + WARN_ON(of_irq_to_resource_table(np, irqr, num_irq) != num_irq);
> +
> +out:
> + return NOTIFY_DONE;
> +}
> +
> /**
> * of_device_alloc - Allocate and initialize an of_device
> * @np: device node to assign to device
> @@ -168,7 +218,13 @@ struct platform_device *of_device_alloc(struct device_node *np,
> rc = of_address_to_resource(np, i, res);
> WARN_ON(rc);
> }
> - WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
> +
> + /* See of_device_resource_notify for populating interrupts */
> + for (i = 0; i < num_irq; i++, res++) {
> + res->flags = IORESOURCE_IRQ;
> + res->start = -EPROBE_DEFER;
> + res->end = -EPROBE_DEFER;
> + }
I actually like the idea of completely allocating the resource structure
but leaving some entries empty. However, I agree with rmk that putting
garbage into a resource structure is a bad idea. What about changing the
value of flags to 0 or some other value to be obviously an empty
property and give the follow up parsing some context about which ones it
needs to attempt to recalculate?
However, I still don't like the notifier approach of actually triggering
the fixup. We need something better.
g.
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