From 6052a15f4a4297b430cf03f2456e51f8d3bb4598 Mon Sep 17 00:00:00 2001 From: Marcin Wojtas Date: Thu, 24 Nov 2016 08:54:33 +0100 Subject: [PATCH] MdeModulePkg/AtaAtapiPassThru: Ensure GHC.AE bit is always set in Ahci According to AHCI Spec 1.3 GHC.AE bit description: "The implementation of this bit is dependent upon the value of the CAP.SAM bit. If CAP.SAM is '0', then GHC.AE shall be read-write and shall have a reset value of '0'. If CAP.SAM is '1', then AE shall be read-only and shall have a reset value of '1'." Being in AhciMode, for proper operation it is required, that GHC.AE bit is always set, before any other AHCI registers are written to. Current AhciMode implementation, both in AhciReset() and AhciModeInitialization() functions, set GHC.AE bit only depending on 'CAP.SAM == 0' condition, assuming (according to the AHCI spec), that otherwise it has to be set anyway. It may however happen, that even if 'CAP.SAM == 1', GHC.AE requires updating by software. This patch enables in AhciMode setting GHC.AE in case its initial value is '0'. It fixes AHCI support for Marvell Armada 70x0 and 80x0 SoC families. The change is transparent to all other platforms. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Marcin Wojtas Signed-off-by: Jan Dabros Reviewed-by: Feng Tian Reviewed-by: Ard Biesheuvel --- .../Bus/Ata/AtaAtapiPassThru/AhciMode.c | 21 +++++++++---------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c index 533d201389..4d01c1dd7f 100644 --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c @@ -1451,17 +1451,13 @@ AhciReset ( { UINT64 Delay; UINT32 Value; - UINT32 Capability; // - // Collect AHCI controller information + // Make sure that GHC.AE bit is set before accessing any AHCI registers. // - Capability = AhciReadReg (PciIo, EFI_AHCI_CAPABILITY_OFFSET); - - // - // Enable AE before accessing any AHCI registers if Supports AHCI Mode Only is not set - // - if ((Capability & EFI_AHCI_CAP_SAM) == 0) { + Value = AhciReadReg(PciIo, EFI_AHCI_GHC_OFFSET); + + if ((Value & EFI_AHCI_GHC_ENABLE) == 0) { AhciOrReg (PciIo, EFI_AHCI_GHC_OFFSET, EFI_AHCI_GHC_ENABLE); } @@ -2252,6 +2248,7 @@ AhciModeInitialization ( EFI_ATA_COLLECTIVE_MODE *SupportedModes; EFI_ATA_TRANSFER_MODE TransferMode; UINT32 PhyDetectDelay; + UINT32 Value; if (Instance == NULL) { return EFI_INVALID_PARAMETER; @@ -2270,11 +2267,13 @@ AhciModeInitialization ( // Collect AHCI controller information // Capability = AhciReadReg (PciIo, EFI_AHCI_CAPABILITY_OFFSET); - + // - // Enable AE before accessing any AHCI registers if Supports AHCI Mode Only is not set + // Make sure that GHC.AE bit is set before accessing any AHCI registers. // - if ((Capability & EFI_AHCI_CAP_SAM) == 0) { + Value = AhciReadReg(PciIo, EFI_AHCI_GHC_OFFSET); + + if ((Value & EFI_AHCI_GHC_ENABLE) == 0) { AhciOrReg (PciIo, EFI_AHCI_GHC_OFFSET, EFI_AHCI_GHC_ENABLE); }