After sending the 1st broadcast INIT-SIPI-SIPI, BSP will collect APs count after one specified timeout delay. However, WakupAp() will restore reset vector immediately after sending 1st broadcast INIT-SIPI-SIPI. Some processors may not complete executing reset vector code.
This fix is to move MicroSecondDelay() from CollectProcessorCount() to the place that is after sending 1st broadcast INIT-SIPI-SIPI and before FreeResetVector() in WakupAp(). Cc: Michael Kinney <[email protected]> Cc: Feng Tian <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <[email protected]> --- UefiCpuPkg/Library/MpInitLib/MpLib.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index fbe2e8b..47a971b 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -513,10 +513,6 @@ CollectProcessorCount ( CpuMpData->InitFlag = ApInitConfig; CpuMpData->X2ApicEnable = FALSE; WakeUpAP (CpuMpData, TRUE, 0, NULL, NULL); - // - // Wait for AP task to complete and then exit. - // - MicroSecondDelay (PcdGet32(PcdCpuApInitTimeOutInMicroSeconds)); CpuMpData->InitFlag = ApInitDone; ASSERT (CpuMpData->CpuCount <= PcdGet32 (PcdCpuMaxLogicalProcessorNumber)); // @@ -863,7 +859,12 @@ WakeUpAP ( // SendInitSipiSipiAllExcludingSelf ((UINT32) ExchangeInfo->BufferStart); } - if (CpuMpData->InitFlag != ApInitConfig) { + if (CpuMpData->InitFlag == ApInitConfig) { + // + // Wait for all potential APs waken up in one specified period + // + MicroSecondDelay (PcdGet32(PcdCpuApInitTimeOutInMicroSeconds)); + } else { // // Wait all APs waken up if this is not the 1st broadcast of SIPI // -- 2.7.4.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
