EmbeddedPkg/MmcDxe: Card Presence Detect Race Condition

The MMC driver defaults to assume a card is not present.  It then starts a timer in MmcDxeInitialize to check for card presence every 200ms.

However it does not immediately check to see if a card is present so if the EFI driver connection process occurs less than 200ms after the driver load, the connection process for partition 
or filesystem drivers will fail because MediaPresent still is FALSE.  To resolve this race condition, we need to immediately perform the presence check in the Start routine.


EmbeddedPkg/MmcDxe: Media ID Handling

Initialize the MMC device on Start or when presence changes instead of doing it on the Block IO calls. This way the layered drivers can be stopped and rebuilt with new Media IDs instead of 
experiencing errors on calls to Block IO.


Proposed-by: Eugene Cohen (HP)
Reviewed-by: oliviermartin




git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12237 6f19259b-4bc3-4df7-8a09-765794883524

3 files changed, 95 insertions, 80 deletions

diff --git a/EmbeddedPkg/Universal/MmcDxe/Mmc.c b/EmbeddedPkg/Universal/MmcDxe/Mmc.c
index cfa9a51..48d3251 100644
--- a/EmbeddedPkg/Universal/MmcDxe/Mmc.c
+++ b/EmbeddedPkg/Universal/MmcDxe/Mmc.c
@@ -299,6 +299,9 @@ MmcDriverBindingStart (
     InsertMmcHost (MmcHostInstance);

 

     MmcHostInstance->Initialized = FALSE;

+

+    // Detect card presence now

+    CheckCardsCallback (NULL, NULL);

   }

 

   return EFI_SUCCESS;

@@ -366,6 +369,10 @@ CheckCardsCallback (
       MmcHostInstance->BlockIo.Media->MediaPresent = !MmcHostInstance->Initialized;

       MmcHostInstance->Initialized = !MmcHostInstance->Initialized;

 

+      if(MmcHostInstance->BlockIo.Media->MediaPresent) {

+        InitializeMmcDevice(MmcHostInstance);

+      }

+

       Status = gBS->ReinstallProtocolInterface (

                     (MmcHostInstance->MmcHandle),

                     &gEfiBlockIoProtocolGuid,

@@ -382,6 +389,7 @@ CheckCardsCallback (
   }

 }

 

+

 EFI_DRIVER_BINDING_PROTOCOL gMmcDriverBinding = {

   MmcDriverBindingSupported,

   MmcDriverBindingStart,

diff --git a/EmbeddedPkg/Universal/MmcDxe/Mmc.h b/EmbeddedPkg/Universal/MmcDxe/Mmc.h
index 2904d91..f3b9029 100644
--- a/EmbeddedPkg/Universal/MmcDxe/Mmc.h
+++ b/EmbeddedPkg/Universal/MmcDxe/Mmc.h
@@ -288,4 +288,15 @@ MmcFlushBlocks (
   IN EFI_BLOCK_IO_PROTOCOL  *This

   );

 

+EFI_STATUS InitializeMmcDevice(

+  IN  MMC_HOST_INSTANCE   *MmcHost

+  );

+

+VOID

+EFIAPI

+CheckCardsCallback (

+  IN  EFI_EVENT   Event,

+  IN  VOID        *Context

+  );

+

 #endif

diff --git a/EmbeddedPkg/Universal/MmcDxe/MmcBlockIo.c b/EmbeddedPkg/Universal/MmcDxe/MmcBlockIo.c
index cc0d5bd..c12411c 100644
--- a/EmbeddedPkg/Universal/MmcDxe/MmcBlockIo.c
+++ b/EmbeddedPkg/Universal/MmcDxe/MmcBlockIo.c
@@ -172,7 +172,6 @@ MmcGetCardStatus(
     Status = MmcHost->SendCommand(MMC_CMD13, CmdArg);

     if (EFI_ERROR(Status)) {

       DEBUG((EFI_D_ERROR, "MmcGetCardStatus(MMC_CMD13): Error and Status = %r\n", Status));

-      ASSERT(0);

       return Status;

     }

 

@@ -305,7 +304,6 @@ MmcIdentificationMode (
 

   if (Timeout == 0) {

     DEBUG((EFI_D_ERROR, "MmcIdentificationMode(): No Card\n"));

-    ASSERT(0);

     return EFI_NO_MEDIA;

   } else {

     PrintOCR(Response[0]);

@@ -320,7 +318,6 @@ MmcIdentificationMode (
   Status = MmcHost->SendCommand(MMC_CMD2, 0);

   if (EFI_ERROR(Status)) {

     DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD2): Error\n"));

-    ASSERT(0);

     return Status;

   }

   MmcHost->ReceiveResponse(MMC_RESPONSE_TYPE_CID,Response);

@@ -363,6 +360,81 @@ MmcIdentificationMode (
   return EFI_SUCCESS;

 }

 

+EFI_STATUS InitializeMmcDevice(

+  IN  MMC_HOST_INSTANCE   *MmcHostInstance

+  )

+{

+  UINT32                  Response[4];

+  EFI_STATUS              Status;

+  UINTN                   CardSize, NumBlocks, BlockSize, CmdArg;

+  EFI_MMC_HOST_PROTOCOL   *MmcHost;

+  UINTN                   BlockCount = 1;

+  

+  MmcHost = MmcHostInstance->MmcHost;

+

+  MmcIdentificationMode (MmcHostInstance);

+

+  //Send a command to get Card specific data

+  CmdArg = MmcHostInstance->CardInfo.RCA << 16;

+  Status = MmcHost->SendCommand(MMC_CMD9, CmdArg);

+  if (EFI_ERROR(Status)) {

+    DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD9): Error, Status=%r\n", Status));

+    return Status;

+  }

+  //Read Response

+  MmcHost->ReceiveResponse(MMC_RESPONSE_TYPE_CSD,Response);

+  PrintCSD(Response);

+

+  if (MmcHostInstance->CardInfo.CardType == SD_CARD_2_HIGH) {

+    CardSize = HC_MMC_CSD_GET_DEVICESIZE(Response);

+    NumBlocks = ((CardSize + 1) * 1024);

+    BlockSize = 1 << MMC_CSD_GET_READBLLEN(Response);

+  } else {

+    CardSize = MMC_CSD_GET_DEVICESIZE(Response);

+    NumBlocks = (CardSize + 1) * (1 << (MMC_CSD_GET_DEVICESIZEMULT(Response) + 2));

+    BlockSize = 1 << MMC_CSD_GET_READBLLEN(Response);

+  }

+

+  //For >=2G card, BlockSize may be 1K, but the transfer size is 512 bytes.

+  if (BlockSize > 512) {

+    NumBlocks = MultU64x32(NumBlocks, BlockSize/512);

+    BlockSize = 512;

+  }

+

+  MmcHostInstance->BlockIo.Media->LastBlock    = (NumBlocks - 1);

+  MmcHostInstance->BlockIo.Media->BlockSize    = BlockSize;

+  MmcHostInstance->BlockIo.Media->ReadOnly     = MmcHost->IsReadOnly();

+  MmcHostInstance->BlockIo.Media->MediaPresent = TRUE;

+  MmcHostInstance->BlockIo.Media->MediaId++;

+

+  CmdArg = MmcHostInstance->CardInfo.RCA << 16;

+  Status = MmcHost->SendCommand(MMC_CMD7, CmdArg);

+  if (EFI_ERROR(Status)) {

+    DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD7): Error and Status = %r\n", Status));

+    return Status;

+  }

+

+  Status = MmcNotifyState (MmcHostInstance, MmcTransferState);

+  if (EFI_ERROR(Status)) {

+    DEBUG((EFI_D_ERROR, "MmcIdentificationMode() : Error MmcTransferState\n"));

+    return Status;

+  }

+

+  // Set Block Length

+  Status = MmcHost->SendCommand(MMC_CMD16, MmcHostInstance->BlockIo.Media->BlockSize);

+  if (EFI_ERROR(Status)) {

+    DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD16): Error MmcHostInstance->BlockIo.Media->BlockSize: %d and Error = %r\n",MmcHostInstance->BlockIo.Media->BlockSize, Status));

+    return Status;

+  }

+

+  // Block Count (not used). Could return an error for SD card

+  if (MmcHostInstance->CardInfo.CardType == MMC_CARD) {

+    MmcHost->SendCommand(MMC_CMD23, BlockCount);

+  }

+

+  return EFI_SUCCESS;

+}

+

 EFI_STATUS

 EFIAPI

 MmcReset (

@@ -424,7 +496,7 @@ MmcIoBlocks (
 {

   UINT32                  Response[4];

   EFI_STATUS              Status;

-  UINTN                   CardSize, NumBlocks, BlockSize, CmdArg;

+  UINTN                   CmdArg;

   INTN                    Timeout;

   UINTN                   Cmd;

   MMC_HOST_INSTANCE       *MmcHostInstance;

@@ -446,89 +518,13 @@ MmcIoBlocks (
     return EFI_NO_MEDIA;

   }

 

-  // If the driver has not been initialized yet then go into Identification Mode

-  if (MmcHostInstance->State == MmcHwInitializationState) {

-    MmcIdentificationMode (MmcHostInstance);

-

-    //Send a command to get Card specific data

-    CmdArg = MmcHostInstance->CardInfo.RCA << 16;

-    Status = MmcHost->SendCommand(MMC_CMD9, CmdArg);

-    if (EFI_ERROR(Status)) {

-      DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD9): Error, Status=%r\n", Status));

-      ASSERT(0);

-      return Status;

-    }

-    //Read Response

-    MmcHost->ReceiveResponse(MMC_RESPONSE_TYPE_CSD,Response);

-    PrintCSD(Response);

-

-    if (MmcHostInstance->CardInfo.CardType == SD_CARD_2_HIGH) {

-      CardSize = HC_MMC_CSD_GET_DEVICESIZE(Response);

-      NumBlocks = ((CardSize + 1) * 1024);

-      BlockSize = 1 << MMC_CSD_GET_READBLLEN(Response);

-    } else {

-      CardSize = MMC_CSD_GET_DEVICESIZE(Response);

-      NumBlocks = (CardSize + 1) * (1 << (MMC_CSD_GET_DEVICESIZEMULT(Response) + 2));

-      BlockSize = 1 << MMC_CSD_GET_READBLLEN(Response);

-    }

-

-    //For >=2G card, BlockSize may be 1K, but the transfer size is 512 bytes.

-    if (BlockSize > 512) {

-      NumBlocks = MultU64x32(NumBlocks, BlockSize/512);

-      BlockSize = 512;

-    }

-

-    MmcHostInstance->BlockIo.Media->LastBlock    = (NumBlocks - 1);

-    MmcHostInstance->BlockIo.Media->BlockSize    = BlockSize;

-    MmcHostInstance->BlockIo.Media->ReadOnly     = MmcHost->IsReadOnly();

-    MmcHostInstance->BlockIo.Media->MediaPresent = TRUE;

-    MmcHostInstance->BlockIo.Media->MediaId++;

-

-    CmdArg = MmcHostInstance->CardInfo.RCA << 16;

-    Status = MmcHost->SendCommand(MMC_CMD7, CmdArg);

-    if (EFI_ERROR(Status)) {

-      DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD7): Error and Status = %r\n", Status));

-      ASSERT(0);

-      return Status;

-    }

-

-    Status = MmcNotifyState (MmcHostInstance, MmcTransferState);

-    if (EFI_ERROR(Status)) {

-      DEBUG((EFI_D_ERROR, "MmcIdentificationMode() : Error MmcTransferState\n"));

-      return Status;

-    }

-

-    // Set Block Length

-    Status = MmcHost->SendCommand(MMC_CMD16, This->Media->BlockSize);

-    if (EFI_ERROR(Status)) {

-      DEBUG((EFI_D_ERROR, "MmcIdentificationMode(MMC_CMD16): Error This->Media->BlockSize: %d and Error = %r\n",This->Media->BlockSize, Status));

-      return Status;

-    }

-

-    // Block Count (not used). Could return an error for SD card

-    if (MmcHostInstance->CardInfo.CardType == MMC_CARD) {

-      MmcHost->SendCommand(MMC_CMD23, BlockCount);

-    }

-  } else {

-    // Maybe test if the card has changed to update gMmcMedia information

-    if (MmcHostInstance->State == MmcTransferState) {

-      //DEBUG((EFI_D_ERROR, "MmcIdentificationMode() : MmcTransferState\n"));

-    } else if (MmcHostInstance->State == MmcStandByState) {

-      DEBUG((EFI_D_ERROR, "MmcIdentificationMode() : MmcStandByState\n"));

-    } else {

-      ASSERT(0);

-    }

-  }

-

   // All blocks must be within the device

   if ((Lba + (BufferSize / This->Media->BlockSize)) > (This->Media->LastBlock + 1)){

-    ASSERT(0);

     return EFI_INVALID_PARAMETER;

   }

 

   // The buffer size must not be zero and it must be an exact multiple of the block size

   if ((BufferSize == 0) || ((BufferSize % This->Media->BlockSize) != 0)) {

-    ASSERT(0);

     return EFI_BAD_BUFFER_SIZE;

   }