On 8 August 2016 at 12:48, Alexei Fedorov <alexei.fedo...@arm.com> wrote: > Please provide the link to the spec which "clearly states that it is the GIC > driver that should be doing it." >
it is not in the spec, but in the comment that you quoted yourself: >>> Looks like it does not: >>> From edk2\EmbeddedPkg\Include\Protocol\HardwareInterrupt.h: >>> >>> " Abstraction for hardware based interrupt routine >>> >>> ...The driver implementing >>> this protocol is responsible for clearing the pending interrupt in the >>> interrupt routing hardware. The HARDWARE_INTERRUPT_HANDLER is responsible >>> for clearing interrupt sources from individual devices." -- Ard. > -----Original Message----- > From: Ard Biesheuvel [mailto:ard.biesheu...@linaro.org] > Sent: 08 August 2016 11:45 > To: Alexei Fedorov > Cc: Evan Lloyd; Cohen, Eugene; edk2-devel@lists.01.org; Heyi Guo; Leif > Lindholm > Subject: Re: [edk2] [PATCH] ArmPkg: Fix double GIC EIOR write per interrupt > > On 8 August 2016 at 12:40, Alexei Fedorov <alexei.fedo...@arm.com> wrote: >> The interrupt is cleared in TimerInterruptHandler() >> (ArmPkg\Drivers\TimerDxe\TimerDxe.c) which is HARDWARE_INTERRUPT_HANDLER >> parameter passed to gInterrupt->RegisterInterruptSource(). > > Indeed. So now, the HARDWARE_INTERRUPT_HANDLER is clearing the interrupt in > the interrupt routing hardware, while the spec clearly states that it is the > GIC driver that should be doing it. > > >> Spurious interrupts which don't have registered interrupt handlers are >> cleared in GicV(2|3)IrqInterruptHandler(). >> > > Yes, that is correct according to the text you quoted. > > -- > Ard. > >> >> -----Original Message----- >> From: Ard Biesheuvel [mailto:ard.biesheu...@linaro.org] >> Sent: 08 August 2016 11:32 >> To: Alexei Fedorov >> Cc: Evan Lloyd; Cohen, Eugene; edk2-devel@lists.01.org; Heyi Guo; Leif >> Lindholm >> Subject: Re: [edk2] [PATCH] ArmPkg: Fix double GIC EIOR write per >> interrupt >> >> On 8 August 2016 at 12:25, Alexei Fedorov <alexei.fedo...@arm.com> wrote: >>> >>>> it does change the contract we have with registered interrupt >>>> handlers >>> >>> Looks like it does not: >>> From edk2\EmbeddedPkg\Include\Protocol\HardwareInterrupt.h: >>> >>> " Abstraction for hardware based interrupt routine >>> >>> ...The driver implementing >>> this protocol is responsible for clearing the pending interrupt in the >>> interrupt routing hardware. The HARDWARE_INTERRUPT_HANDLER is responsible >>> for clearing interrupt sources from individual devices." >>> >> >> Thanks for digging that up! >> >> So after this change, the driver implementing the hardware interrupt >> protocol no longer clears the pending interrupt in the interrupt routing >> hardware. This means that we are not only changing the existing contract, we >> are also violating the spec. >> >> >>> >>> -----Original Message----- >>> From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf >>> Of Ard Biesheuvel >>> Sent: 06 August 2016 09:25 >>> To: Evan Lloyd; Cohen, Eugene >>> Cc: edk2-devel@lists.01.org; Heyi Guo; Leif Lindholm >>> Subject: Re: [edk2] [PATCH] ArmPkg: Fix double GIC EIOR write per >>> interrupt >>> >>> (+ Eugene) >>> >>> On 5 August 2016 at 18:59, <evan.ll...@arm.com> wrote: >>>> From: Alexei <alexei.fedo...@arm.com> >>>> >>>> This commit fixes a bug in the GIC v2 and v3 drivers where the >>>> GICC_EOIR (End Of Interrupt Register) is written twice for a single >>>> interrupt. >>>> GicV(2|3)IrqInterruptHandler() calls the Interrupt Handler and then >>>> GicV(2|3)EndOfInterrupt() on exit: >>>> >>>> InterruptHandler = gRegisteredInterruptHandlers[GicInterrupt]; >>>> if (InterruptHandler != NULL) { >>>> // Call the registered interrupt handler. >>>> InterruptHandler (GicInterrupt, SystemContext); } else { >>>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>>> GicInterrupt)); } >>>> >>>> GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, GicInterrupt); >>>> >>>> , although gInterrupt->EndOfInterrupt() has already been called by >>>> InterruptHandler(). >>>> >>>> The fix moves the EndOfInterrupt() call inside the else case for >>>> unregistered/spurious interrupts. This removes a potential race >>>> condition that might have lost interrupts. >>>> >>> >>> I understand that this solves the problem, but it does change the contract >>> we have with registered interrupt handlers, and we don't know how this may >>> be used out of tree. I know UEFI only supports polling for drivers, but are >>> there any other cases (debug?) where we may break other people's code by >>> doing this? >>> >>> >>>> Contributed-under: TianoCore Contribution Agreement 1.0 >>>> Signed-off-by: Alexei Fedorov <alexei.fedo...@arm.com> >>>> Signed-off-by: Evan Lloyd <evan.ll...@arm.com> >>>> --- >>>> >>>> Code is available at: >>>> https://github.com/EvanLloyd/tianocore/tree/EOIR_v1 >>>> >>>> ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c | 5 ++--- >>>> ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c | 5 ++--- >>>> 2 files changed, 4 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>>> b/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>>> index >>>> 036eb5cd6bf6845dd2b03b62c933c1dedaef7251..34d4be3867647e0fdad7356c94 >>>> 9 >>>> a >>>> f8cd3ede7164 100644 >>>> --- a/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>>> +++ b/ArmPkg/Drivers/ArmGic/GicV2/ArmGicV2Dxe.c >>>> @@ -2,7 +2,7 @@ >>>> >>>> Copyright (c) 2009, Hewlett-Packard Company. All rights >>>> reserved.<BR> Portions copyright (c) 2010, Apple Inc. All rights >>>> reserved.<BR> -Portions copyright (c) 2011-2015, ARM Ltd. All rights >>>> reserved.<BR> >>>> +Portions copyright (c) 2011-2016, ARM Ltd. All rights reserved.<BR> >>>> >>>> This program and the accompanying materials are licensed and made >>>> available under the terms and conditions of the BSD License @@ >>>> -178,9 >>>> +178,8 @@ GicV2IrqInterruptHandler ( >>>> InterruptHandler (GicInterrupt, SystemContext); >>>> } else { >>>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>>> GicInterrupt)); >>>> + GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, >>>> + GicInterrupt); >>>> } >>>> - >>>> - GicV2EndOfInterrupt (&gHardwareInterruptV2Protocol, >>>> GicInterrupt); } >>>> >>>> // >>>> diff --git a/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>>> b/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>>> index >>>> 106c669fcb8777dfaad609c0ce9f5b572727a3ff..983936f3738a74bb5d5e08e012 >>>> 9 >>>> 7 >>>> 3df240958a8b 100644 >>>> --- a/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>>> +++ b/ArmPkg/Drivers/ArmGic/GicV3/ArmGicV3Dxe.c >>>> @@ -1,6 +1,6 @@ >>>> /** @file >>>> * >>>> -* Copyright (c) 2011-2015, ARM Limited. All rights reserved. >>>> +* Copyright (c) 2011-2016, ARM Limited. All rights reserved. >>>> * >>>> * This program and the accompanying materials >>>> * are licensed and made available under the terms and conditions >>>> of the BSD License @@ -169,9 +169,8 @@ GicV3IrqInterruptHandler ( >>>> InterruptHandler (GicInterrupt, SystemContext); >>>> } else { >>>> DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", >>>> GicInterrupt)); >>>> + GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, >>>> + GicInterrupt); >>>> } >>>> - >>>> - GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, >>>> GicInterrupt); } >>>> >>>> // >>>> -- >>>> Guid("CE165669-3EF3-493F-B85D-6190EE5B9759") >>>> >>> _______________________________________________ >>> edk2-devel mailing list >>> edk2-devel@lists.01.org >>> https://lists.01.org/mailman/listinfo/edk2-devel >>> >>> IMPORTANT NOTICE: The contents of this email and any attachments are >>> confidential and may also be privileged. If you are not the intended >>> recipient, please notify the sender immediately and do not disclose the >>> contents to any other person, use it for any purpose, or store or copy the >>> information in any medium. Thank you. >>> >> >> IMPORTANT NOTICE: The contents of this email and any attachments are >> confidential and may also be privileged. If you are not the intended >> recipient, please notify the sender immediately and do not disclose the >> contents to any other person, use it for any purpose, or store or copy the >> information in any medium. Thank you. > > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. 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