diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/VtdReg.c b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/VtdReg.c index 8dbc83fa2d..e564d373c7 100644 --- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/VtdReg.c +++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/VtdReg.c @@ -554,11 +554,13 @@ DumpVtdIfError ( for (Index = 0; Index < (UINTN)CapReg.Bits.NFR + 1; Index++) { FrcdReg.Uint64[1] = MmioRead64 (mVtdUnitInformation[Num].VtdUnitBaseAddress + ((CapReg.Bits.FRO * 16) + (Index * 16) + R_FRCD_REG + sizeof(UINT64))); if (FrcdReg.Bits.F != 0) { - FrcdReg.Bits.F = 0; + // + // Software writes the value read from this field (F) to Clear it. + // MmioWrite64 (mVtdUnitInformation[Num].VtdUnitBaseAddress + ((CapReg.Bits.FRO * 16) + (Index * 16) + R_FRCD_REG + sizeof(UINT64)), FrcdReg.Uint64[1]); } - MmioWrite32 (mVtdUnitInformation[Num].VtdUnitBaseAddress + R_FSTS_REG, MmioRead32 (mVtdUnitInformation[Num].VtdUnitBaseAddress + R_FSTS_REG)); } + MmioWrite32 (mVtdUnitInformation[Num].VtdUnitBaseAddress + R_FSTS_REG, MmioRead32 (mVtdUnitInformation[Num].VtdUnitBaseAddress + R_FSTS_REG)); } } }