From: "Cohen, Eugene" <eug...@hp.com>
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1583
The SdMmcPciHcDriverBindingStart function was checking two different
capability bits in determining whether 64-bit DMA modes were supported,
one mode is defined in the SDHC version 3 specification (using 96-bit
descriptors) and another is defined in the SDHC version 4 specification
(using 128-bit descriptors).
Since the currently implementation of 64-bit ADMA2 only supports the SDHC
version 4 implementation, it is incorrect to check the V3 64-bit
capability bit since this will activate V4 ADMA2 on V3 controllers which
then causes buffers to be allocated that cannot be DMAed.
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Ashish Singhal <ashishsin...@nvidia.com>
Cc: Hao Wu <hao.a...@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Eugene Cohen <eug...@hp.com>
Acked-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Acked-by: Ashish Singhal <ashishsin...@nvidia.com>
Reviewed-by: Hao Wu <hao.a...@intel.com>
---
MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c
b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c
index b474f8decd..5bc91c5337 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHcDxe.c
@@ -666,8 +666,7 @@ SdMmcPciHcDriverBindingStart (
// If any of the slots does not support 64b system bus
// do not enable 64b DMA in the PCI layer.
//
- if (Private->Capability[Slot].SysBus64V3 == 0 &&
- Private->Capability[Slot].SysBus64V4 == 0) {
+ if (Private->Capability[Slot].SysBus64V4 == 0) {
Support64BitDma = FALSE;
}
--
2.12.0.windows.1
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