Re: [PATCH V9 1/3] ACPI: Generic GSI: Do not attempt to map non-GSI IRQs during bus scan

From: Hanjun Guo
Date: Tue Jan 17 2017 - 07:22:46 EST


On 2016/12/15 6:10, Agustin Vega-Frias wrote:
> ACPI extended IRQ resources may contain a Resource Source field to specify
> an alternate interrupt controller, attempting to map them as GSIs is
> incorrect, so just disable the platform resource.
>
> Since this field is currently ignored, we make this change conditional
> on CONFIG_ACPI_GENERIC_GSI to keep the current behavior on x86 platforms,
> in case some existing ACPI tables are using this incorrectly.
>
> Signed-off-by: Agustin Vega-Frias <agustinv@xxxxxxxxxxxxxx>
> ---
> drivers/acpi/resource.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 56241eb..76ca4e9 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -43,6 +43,18 @@ static inline bool acpi_iospace_resource_valid(struct resource *res)
> acpi_iospace_resource_valid(struct resource *res) { return true; }
> #endif
>
> +#ifdef CONFIG_ACPI_GENERIC_GSI
> +static inline bool is_gsi(struct acpi_resource_extended_irq *ext_irq)
> +{
> + return ext_irq->resource_source.string_length == 0;

As pointed out by Lorenzo, if the interrupt resource is a Resource Producer,
it's not GSI, so maybe the code needs to be updated as

- return ext_irq->resource_source.string_length == 0;
+ return ext_irq->resource_source.string_length == 0 &&
+ ext_irq->producer_consumer != ACPI_PRODUCER;

Thanks
Hanjun