BTW, this kind of change begs for a comment, how about:
default:
/*
* Even if we don't know the GPE type, make sure that we always
* disable it. This can prevent a certain type of GPE flood,
where
* the GPE has no _Lxx/_Exx method, and it cannot be determined
* whether the GPE is wake, run, or wake/run.
*/
Status = AcpiHwWriteGpeEnableReg (GpeEventInfo);
break;
>-----Original Message-----
>From: Len Brown [mailto:lenb@xxxxxxxxxx]
>Sent: Tuesday, November 20, 2007 10:43 AM
>To: Moore, Robert
>Cc: linux-acpi@xxxxxxxxxxxxxxx; Zhang, Rui; Alexey Starikovskiy
>Subject: ACPI: disable stray GPE, prevent ACPI interrupt storm
>
>Bob,
>Rui's Linux patch below modifies an ACPICA file.
>
>thanks,
>-Len
>
>commit a7f9b1f24974da287771e2d70b30d9ca7bd66684
>Author: Zhang Rui <rui.zhang@xxxxxxxxx>
>Date: Tue Nov 20 13:38:59 2007 -0500
>
> ACPI: disable stray GPE, prevent ACPI interrupt storm
>
> GPEs are disabled depending on their type --
> WAKE, WAKE_RUN, and RUNTIME. An error is returned
> if we are asked to disable a GPE that has no type.
>
> But at least one system exists that enables a GPE from AML
> that is not the EC GPE, and has no _Lxx/_Exx AML handler,
> and is thus never initialized.
>
> In this case, when an external CRT is plugged in,
> the GPE fires, we attempt to disable the GPE,
> but instead just return an error.
> So the GPE stays asserted and an ACPI interrupt storm follows.
>
> The fix is to disable a firing GPE,
> even if it comes from outer space.
>
> http://bugzilla.kernel.org/show_bug.cgi?id=6217
>
> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> Acked-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
> Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
>
>diff --git a/drivers/acpi/events/evgpe.c b/drivers/acpi/events/evgpe.c
>index e22f4a9..056b788 100644
>--- a/drivers/acpi/events/evgpe.c
>+++ b/drivers/acpi/events/evgpe.c
>@@ -270,18 +270,18 @@ acpi_status acpi_ev_disable_gpe(struct
>acpi_gpe_event_info *gpe_event_info)
> case ACPI_GPE_TYPE_WAKE_RUN:
> ACPI_CLEAR_BIT(gpe_event_info->flags,
ACPI_GPE_WAKE_ENABLED);
>
>- /*lint -fallthrough */
>+ /* fallthrough */
>
> case ACPI_GPE_TYPE_RUNTIME:
>
> /* Disable the requested runtime GPE */
>
> ACPI_CLEAR_BIT(gpe_event_info->flags,
ACPI_GPE_RUN_ENABLED);
>- status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
>- break;
>+
>+ /* fallthrough */
>
> default:
>- return_ACPI_STATUS(AE_BAD_PARAMETER);
>+ acpi_hw_write_gpe_enable_reg(gpe_event_info);
> }
>
> return_ACPI_STATUS(AE_OK);
-
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