REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1483
Due to the limited resource on the VTd DMA buffer size in the PEI phase,
the driver will limit the maximum transfer block number for 48-bit
addressing.
This commit aims to prevent the potential failure on calls to the IOMMU
'Map' service.
Cc: Ray Ni <ray...@intel.com>
Cc: Eric Dong <eric.d...@intel.com>
Cc: Jian J Wang <jian.j.w...@intel.com>
Signed-off-by: Hao Wu <hao.a...@intel.com>
---
MdeModulePkg/Bus/Ata/AhciPei/AhciMode.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/MdeModulePkg/Bus/Ata/AhciPei/AhciMode.c
b/MdeModulePkg/Bus/Ata/AhciPei/AhciMode.c
index a83c213a47..f9174e68b1 100644
--- a/MdeModulePkg/Bus/Ata/AhciPei/AhciMode.c
+++ b/MdeModulePkg/Bus/Ata/AhciPei/AhciMode.c
@@ -48,7 +48,12 @@ UINT8 mAtaTrustCommands[2] = {
// Look up table (Lba48Bit) for maximum transfer block number
//
#define MAX_28BIT_TRANSFER_BLOCK_NUM 0x100
-#define MAX_48BIT_TRANSFER_BLOCK_NUM 0xFFFF
+//
+// Due to limited resource on VTd PEI DMA buffer size, driver limits the
+// maximum transfer block number for 48-bit addressing.
+// Setting to 0x800 here means 1M bytes for device with 512-byte block size.
+//
+#define MAX_48BIT_TRANSFER_BLOCK_NUM 0x800
UINT32 mMaxTransferBlockNumber[2] = {
MAX_28BIT_TRANSFER_BLOCK_NUM,
--
2.12.0.windows.1
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