[PATCH] MdeModulePkg/SdMmcPciHcDxe: Use 16/32-bit IO widths

[Jeff Brasen <jbrasen@nvidia.com>]

From: Edgar Handal <ehandal@nvidia.com>

Use 16-bit and 32-bit IO widths for SDMMC MMIO to prevent all register
accesses from being split up into 8-bit accesses.

The SDHCI specification states that the registers shall be accessable in
byte, word, and double word accesses.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
---
 MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c | 25 ++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
index 5aec8c6..82f4493 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
@@ -152,19 +152,36 @@ SdMmcHcRwMmio (
   )
 {
   EFI_STATUS                   Status;
+  EFI_PCI_IO_PROTOCOL_WIDTH    Width;
 
   if ((PciIo == NULL) || (Data == NULL))  {
     return EFI_INVALID_PARAMETER;
   }
 
-  if ((Count != 1) && (Count != 2) && (Count != 4) && (Count != 8)) {
-    return EFI_INVALID_PARAMETER;
+  switch (Count) {
+    case 1:
+      Width = EfiPciIoWidthUint8;
+      break;
+    case 2:
+      Width = EfiPciIoWidthUint16;
+      Count = 1;
+      break;
+    case 4:
+      Width = EfiPciIoWidthUint32;
+      Count = 1;
+      break;
+    case 8:
+      Width = EfiPciIoWidthUint32;
+      Count = 2;
+      break;
+    default:
+      return EFI_INVALID_PARAMETER;
   }
 
   if (Read) {
     Status = PciIo->Mem.Read (
                           PciIo,
-                          EfiPciIoWidthUint8,
+                          Width,
                           BarIndex,
                           (UINT64) Offset,
                           Count,
@@ -173,7 +190,7 @@ SdMmcHcRwMmio (
   } else {
     Status = PciIo->Mem.Write (
                           PciIo,
-                          EfiPciIoWidthUint8,
+                          Width,
                           BarIndex,
                           (UINT64) Offset,
                           Count,
-- 
2.7.4