.. in case the platform does not received the used buffer from the device, VirtioFlush() returns EFI_TIMEOUT.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Olivier Martin <olivier.mar...@arm.com> --- OvmfPkg/Include/Library/VirtioLib.h | 3 +++ OvmfPkg/Library/VirtioLib/VirtioLib.c | 16 ++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/OvmfPkg/Include/Library/VirtioLib.h b/OvmfPkg/Include/Library/VirtioLib.h index 36527a5..62f6811 100644 --- a/OvmfPkg/Include/Library/VirtioLib.h +++ b/OvmfPkg/Include/Library/VirtioLib.h @@ -170,6 +170,9 @@ VirtioAppendDesc ( @return Error code from VirtIo->SetQueueNotify() if it fails. + @retval EFI_TIMEOUT If it did not received the used buffer from the device + in approximatively less than 10ms + @retval EFI_SUCCESS Otherwise, the host processed all descriptors. **/ diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c b/OvmfPkg/Library/VirtioLib/VirtioLib.c index 54cf225..566f596 100644 --- a/OvmfPkg/Library/VirtioLib/VirtioLib.c +++ b/OvmfPkg/Library/VirtioLib/VirtioLib.c @@ -3,7 +3,7 @@ Utility functions used by virtio device drivers. Copyright (C) 2012, Red Hat, Inc. - Portion of Copyright (C) 2013, ARM Ltd. + Portion of Copyright (C) 2013-2014, ARM Ltd. This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this @@ -252,6 +252,9 @@ VirtioAppendDesc ( @return Error code from VirtIo->SetQueueNotify() if it fails. + @retval EFI_TIMEOUT If it did not received the used buffer from the device + in approximatively less than 10ms + @retval EFI_SUCCESS Otherwise, the host processed all descriptors. **/ @@ -267,6 +270,7 @@ VirtioFlush ( UINT16 NextAvailIdx; EFI_STATUS Status; UINTN PollPeriodUsecs; + UINTN Timeout; // // virtio-0.9.5, 2.4.1.2 Updating the Available Ring @@ -304,16 +308,24 @@ VirtioFlush ( // Keep slowing down until we reach a poll period of slightly above 1 ms. // PollPeriodUsecs = 1; + Timeout = 0; MemoryFence(); - while (*Ring->Used.Idx != NextAvailIdx) { + while ((*Ring->Used.Idx != NextAvailIdx) && (Timeout < 10)) { gBS->Stall (PollPeriodUsecs); // calls AcpiTimerLib::MicroSecondDelay if (PollPeriodUsecs < 1024) { PollPeriodUsecs *= 2; + } else { + Timeout++; } MemoryFence(); } MemoryFence(); + + if (Timeout == 10) { + return EFI_TIMEOUT; + } + return EFI_SUCCESS; } -- 2.1.1 ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ edk2-devel mailing list edk2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/edk2-devel