On Sun, Nov 13, 2016 at 04:59:33PM -0500, Agustin Vega-Frias wrote:
> This allows probe deferral to work properly when a dependent device
> fails to get a valid IRQ because the IRQ domain was not registered
> at the time the resources were added to the platform_device.
>
> Signed-off-by: Agustin Vega-Frias <agustinv@xxxxxxxxxxxxxx>
> ---
> drivers/acpi/resource.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/base/platform.c | 9 +++++++-
> include/linux/acpi.h | 7 ++++++
> 3 files changed, 74 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 56241eb..4beda15 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -664,3 +664,62 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares,
> return (type & types) ? 0 : 1;
> }
> EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);
> +
> +struct acpi_irq_get_ctx {
> + unsigned int index;
> + struct resource *res;
> +};
> +
> +static acpi_status acpi_irq_get_cb(struct acpi_resource *ares, void *context)
> +{
> + struct acpi_irq_get_ctx *ctx = context;
> + struct acpi_resource_irq *irq;
> + struct acpi_resource_extended_irq *ext_irq;
> +
> + switch (ares->type) {
> + case ACPI_RESOURCE_TYPE_IRQ:
> + irq = &ares->data.irq;
> + if (ctx->index < irq->interrupt_count) {
> + acpi_dev_resource_interrupt(ares, ctx->index, ctx->res);
> + return AE_CTRL_TERMINATE;
> + }
> + ctx->index -= irq->interrupt_count;
I do not understand this code, mind explaining what it is meant to do ?
In particular I do not understand the logic behind the index decrement,
I think I am missing something here.
> + break;
> + case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> + ext_irq = &ares->data.extended_irq;
> + if (ctx->index < ext_irq->interrupt_count) {
> + acpi_dev_resource_interrupt(ares, ctx->index, ctx->res);
> + return AE_CTRL_TERMINATE;
> + }
> + ctx->index -= ext_irq->interrupt_count;
Ditto.
Thanks,
Lorenzo
> + break;
> + }
> +
> + return AE_OK;
> +}
> +
> +/**
> + * acpi_irq_get - Look for the ACPI IRQ resource with the given index and
> + * use it to initialize the given Linux IRQ resource.
> + * @handle ACPI device handle
> + * @index ACPI IRQ resource index to lookup
> + * @res Linux IRQ resource to initialize
> + *
> + * Return: 0 on success
> + * -EINVAL if an error occurs
> + * -EPROBE_DEFER if the IRQ lookup/conversion failed
> + */
> +int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
> +{
> + struct acpi_irq_get_ctx ctx = { index, res };
> + acpi_status status;
> +
> + status = acpi_walk_resources(handle, METHOD_NAME__CRS,
> + acpi_irq_get_cb, &ctx);
> + if (ACPI_FAILURE(status))
> + return -EINVAL;
> + if (res->flags & IORESOURCE_DISABLED)
> + return -EPROBE_DEFER;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(acpi_irq_get);
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index c4af003..61423d2 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -102,6 +102,14 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
> }
>
> r = platform_get_resource(dev, IORESOURCE_IRQ, num);
> + if (r && r->flags & IORESOURCE_DISABLED && ACPI_COMPANION(&dev->dev)) {
> + int ret;
> +
> + ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
> + if (ret)
> + return ret;
> + }
> +
> /*
> * The resources may pass trigger flags to the irqs that need
> * to be set up. It so happens that the trigger flags for
> @@ -1450,4 +1458,3 @@ void __init early_platform_cleanup(void)
> memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
> }
> }
> -
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 689a8b9..325bdb9 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -406,6 +406,7 @@ bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
> unsigned int acpi_dev_get_irq_type(int triggering, int polarity);
> bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
> struct resource *res);
> +int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
>
> void acpi_dev_free_resource_list(struct list_head *list);
> int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
> @@ -763,6 +764,12 @@ static inline int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
> return -EINVAL;
> }
>
> +static inline int acpi_irq_get(acpi_handle handle, unsigned int index,
> + struct resource *res)
> +{
> + return -EINVAL;
> +}
> +
> #endif /* !CONFIG_ACPI */
>
> #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
> --
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> Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
>
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