On Wed, Jun 9, 2021 at 4:14 AM Hui Wang <hui.wang@xxxxxxxxxxxxx> wrote:
>
> The laptop keyboard doesn't work on many MEDION notebooks, but the
> keyboard works well under Windows and Unix.
>
> Through debugging, we found this log in the dmesg:
> ACPI: IRQ 1 override to edge, high
> pnp 00:03: Plug and Play ACPI device, IDs PNP0303 (active)
>
> And we checked the IRQ definition in the DSDT, it is:
> IRQ (Level, ActiveLow, Exclusive, )
> {1}
>
> So the BIOS defines the keyboard irq to Level_Low, but the linux
> kernel override it to Edge_High. If let the linux kernel skip the irq
> override, the keyboard will work normally.
>
> From the existing comment in the acpi_dev_get_irqresource(), the
> override function only needs to be called when BIOS defines IRQ() or
> IRQNoFlags, and according to the Section 6.4.2.1 of ACPI 6.4 spec [1],
> if IRQ() is empty or defines IRQNoFlags, the IRQ is High true, edge
> sensitive and non-shareable. The linux ACPI driver (acpi_rs_set_irq[]
> in rsirq.c) also assumes so.
>
> Here check 3 conditions to decide if the legacy is true or not, if it
> is true, it means the IRQ() is empty or defines IRQNoFlags and need to
> call irq_override().
>
> Link: https://uefi.org/specs/ACPI/6.4/06_Device_Configuration/Device_Configuration.html#irq-descriptor # [1]
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=213031
> BugLink: http://bugs.launchpad.net/bugs/1909814
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Reported-and-tested-by: Manuel Krause <manuelkrause@xxxxxxxxxxxx>
> Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx>
> ---
> drivers/acpi/resource.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index ee78a210c606..dc01fb550b28 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -423,6 +423,13 @@ static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
> }
> }
>
> +static bool irq_is_legacy(struct acpi_resource_irq *irq)
> +{
> + return irq->triggering == ACPI_EDGE_SENSITIVE &&
> + irq->polarity == ACPI_ACTIVE_HIGH &&
> + irq->shareable == ACPI_EXCLUSIVE;
> +}
> +
> /**
> * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
> * @ares: Input ACPI resource object.
> @@ -461,7 +468,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
> }
> acpi_dev_get_irqresource(res, irq->interrupts[index],
> irq->triggering, irq->polarity,
> - irq->shareable, true);
> + irq->shareable, irq_is_legacy(irq));
> break;
> case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> ext_irq = &ares->data.extended_irq;
> --
Applied as 5.14 material under a new subject ("ACPI: resources: Add
checks for ACPI IRQ override") and with some edits in the patch
changelog.
Note, however, that this is a change in behavior that may result in
regressions on old machines, in which case some further refinements of
the code will be necessary.
Thanks!
