Re: [RFC] SATA : Implemented NXP errata A008402

["Zeng, Star" <star.zeng@intel.com>]

Do you have a full patch already?
Why the PcdPrdtMaxDataLength is defined to 0x3FFFFF, but not 0x400000?


Thanks,
Star
-----Original Message-----
From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Meenakshi Aggarwal
Sent: Monday, January 8, 2018 7:17 PM
To: ard.biesheuvel@linaro.org; leif.lindholm@linaro.org; edk2-devel@lists.01.org; Zeng, Star <star.zeng@intel.com>; Dong, Eric <eric.dong@intel.com>
Subject: [edk2] [RFC] SATA : Implemented NXP errata A008402

Description:
Commands with 4 MB PRD length entries fail if PRD[DBC] is
set to the value according to AHCI standard spec.
Due to a logic error, 3F_FFFFh is misinterpreted by the
device as zero length.

Workaround:
Set PRD length to 0 when creating a PRD entry for
a maximum data transfer size of 4 MB to fix the erratum.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com>
---
 MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c           | 2 +-
 MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf | 1 +
 MdeModulePkg/MdeModulePkg.dec                              | 3 +++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
index e6de5d6..fb6dc0b 100644
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
@@ -591,7 +591,7 @@ AhciBuildCommand (
     if (RemainedData < EFI_AHCI_MAX_DATA_PER_PRDT) {
       AhciRegisters->AhciCommandTable->PrdtTable[PrdtIndex].AhciPrdtDbc = (UINT32)RemainedData - 1;
     } else {
-      AhciRegisters->AhciCommandTable->PrdtTable[PrdtIndex].AhciPrdtDbc = EFI_AHCI_MAX_DATA_PER_PRDT - 1;
+      AhciRegisters->AhciCommandTable->PrdtTable[PrdtIndex].AhciPrdtDbc = PcdGet32 (PcdPrdtMaxDataLength);
     }
 
     Data64.Uint64 = (UINT64)MemAddr;
diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
index 82d5f7a..8921dd5 100644
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
@@ -70,6 +70,7 @@
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdAtaSmartEnable   ## SOMETIMES_CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPrdtMaxDataLength
 
 # [Event]
 # EVENT_TYPE_PERIODIC_TIMER ## SOMETIMES_CONSUMES
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 8efad57..b2f9f2b 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -1434,6 +1434,9 @@
   # @Prompt Console Output Row of Text Setup
   gEfiMdeModulePkgTokenSpaceGuid.PcdSetupConOutRow|25|UINT32|0x4000000e
 
+  ## This PCD specifies the Maximum data length for a PRD Entry
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPrdtMaxDataLength|0x3FFFFF|UINT32|0x4000000f
+
 [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
   ## UART clock frequency is for the baud rate configuration.
   # @Prompt Serial Port Clock Rate.
-- 
1.9.1

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