[PATCH v2 6/7] EmbeddedPkg: Fix DwEmmc SendCommand polling

["Loh, Tien Hock" <tien.hock.loh@intel.com>]

From: "Tien Hock, Loh" <tien.hock.loh@intel.com>

Change SendCommand polling mode to remove unnecessary delay, and check
for transfer done only when block data is to be read/write. This would
also increase performance slightly.

Signed-off-by: "Tien Hock, Loh" <tien.hock.loh@intel.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c | 43 +++++++++++++++-----
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
index c6c8e04917..b57833458f 100644
--- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
+++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
@@ -286,16 +286,13 @@ SendCommand (
             DWEMMC_INT_RCRC | DWEMMC_INT_RE;
   ErrMask |= DWEMMC_INT_DCRC | DWEMMC_INT_DRT | DWEMMC_INT_SBE;
   do {
-    MicroSecondDelay(500);
     Data = MmioRead32 (DWEMMC_RINTSTS);
-
-    if (Data & ErrMask) {
-      return EFI_DEVICE_ERROR;
-    }
-    if (Data & DWEMMC_INT_DTO) {     // Transfer Done
-      break;
-    }
   } while (!(Data & DWEMMC_INT_CMD_DONE));
+
+  if (Data & ErrMask) {
+    return EFI_DEVICE_ERROR;
+  }
+
   return EFI_SUCCESS;
 }
 
@@ -550,8 +547,9 @@ DwEmmcReadBlockData (
   )
 {
   EFI_STATUS  Status;
-  UINT32      DescPages, CountPerPage, Count;
+  UINT32      DescPages, CountPerPage, Count, ErrMask;
   EFI_TPL     Tpl;
+  UINTN Rintsts = 0;
 
   Tpl = gBS->RaiseTPL (TPL_NOTIFY);
 
@@ -574,6 +572,18 @@ DwEmmcReadBlockData (
     DEBUG ((DEBUG_ERROR, "Failed to read data, mDwEmmcCommand:%x, mDwEmmcArgument:%x, Status:%r\n", mDwEmmcCommand, mDwEmmcArgument, Status));
     goto out;
   }
+
+  while(!((MmioRead32(DWEMMC_RINTSTS) & (DWEMMC_INT_DTO)))) {
+    Rintsts = MmioRead32 (DWEMMC_RINTSTS);
+  }
+  ErrMask = DWEMMC_INT_EBE | DWEMMC_INT_HLE | DWEMMC_INT_RTO |
+            DWEMMC_INT_RCRC | DWEMMC_INT_RE | DWEMMC_INT_DCRC |
+            DWEMMC_INT_DRT | DWEMMC_INT_SBE;
+
+  if (Rintsts & ErrMask) {
+    Status = EFI_DEVICE_ERROR;
+    goto out;
+  }
 out:
   // Restore Tpl
   gBS->RestoreTPL (Tpl);
@@ -589,8 +599,9 @@ DwEmmcWriteBlockData (
   )
 {
   EFI_STATUS  Status;
-  UINT32      DescPages, CountPerPage, Count;
+  UINT32      DescPages, CountPerPage, Count, ErrMask;
   EFI_TPL     Tpl;
+  UINTN Rintsts = 0;
 
   Tpl = gBS->RaiseTPL (TPL_NOTIFY);
 
@@ -613,6 +624,18 @@ DwEmmcWriteBlockData (
     DEBUG ((DEBUG_ERROR, "Failed to write data, mDwEmmcCommand:%x, mDwEmmcArgument:%x, Status:%r\n", mDwEmmcCommand, mDwEmmcArgument, Status));
     goto out;
   }
+
+  while(!((MmioRead32(DWEMMC_RINTSTS) & (DWEMMC_INT_DTO)))) {
+    Rintsts = MmioRead32 (DWEMMC_RINTSTS);
+  }
+  ErrMask = DWEMMC_INT_EBE | DWEMMC_INT_HLE | DWEMMC_INT_RTO |
+            DWEMMC_INT_RCRC | DWEMMC_INT_RE | DWEMMC_INT_DCRC |
+            DWEMMC_INT_DRT | DWEMMC_INT_SBE;
+
+  if (Rintsts & ErrMask) {
+    Status = EFI_DEVICE_ERROR;
+    goto out;
+  }
 out:
   // Restore Tpl
   gBS->RestoreTPL (Tpl);
-- 
2.19.0