Re: [PATCH v3] ACPI : don't always override the acpi irq

Manuel Krause <manuelkrause@xxxxxxxxxxxx> · Wed, 9 Jun 2021 17:06:27 +0200

On 09/06/2021 14:44, Rafael J. Wysocki wrote:
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!


I just want to assure you, that also [PATCH v3] works fine on here.
Maybe I can find some time to re-activate my other, over 12 years 
old, HP notebook and check for possible issues with this patch.

I have to thank you all for your great work!

Best regards,
Manuel






