I don't understand why the GPE was enabled in the first place. GPEs start out all disabled. They only get enabled if an _Lxx/_Exx method is found. I'm all for defensive programming (if all else fails...), but I'm worried that there is a bug somewhere else that is accidentally enabling this GPE. >> > 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. Yes, it should be "initialized". All GPEs are disabled by default. Please check this out. Thanks, Bob >-----Original Message----- >From: Zhang, Rui >Sent: Tuesday, November 20, 2007 5:33 PM >To: Moore, Robert >Cc: Len Brown; linux-acpi@xxxxxxxxxxxxxxx; Alexey Starikovskiy >Subject: RE: ACPI: disable stray GPE, prevent ACPI interrupt storm > > >On Wed, 2007-11-21 at 07:11 +0800, Moore, Robert wrote: >> BTW, this kind of change begs for a comment >> >Sounds good. :) > >Thanks, >Rui >> 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); - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
