[platforms: PATCH 01/10] Marvell/Drivers: MvI2cDxe: Abort transaction immediately upon fail

[Marcin Wojtas <mw@semihalf.com>]

From: David Greeson <dgreeson@cisco.com>

Although the I2C transaction routines were prepared to
return their status, they were never used. This could
cause bus lock-up e.g. in case of failing to send a
slave address, the data transfer was attempted to be
continued anyway.

This patch fixes faulty behavior by checking transaction
status and stopping it immediately, once the fail
is detected.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: David Greeson <dgreeson@cisco.com>
[Style adjustment and cleanup]
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
---
 Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c | 34 +++++++++++++++++---
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c b/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
index d85ee0b..7faf1f7 100755
--- a/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
+++ b/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
@@ -565,6 +565,7 @@ MvI2cStartRequest (
   UINTN Transmitted;
   I2C_MASTER_CONTEXT *I2cMasterContext = I2C_SC_FROM_MASTER(This);
   EFI_I2C_OPERATION *Operation;
+  EFI_STATUS Status = EFI_SUCCESS;
 
   ASSERT (RequestPacket != NULL);
   ASSERT (I2cMasterContext != NULL);
@@ -574,35 +575,58 @@ MvI2cStartRequest (
     ReadMode = Operation->Flags & I2C_FLAG_READ;
 
     if (Count == 0) {
-      MvI2cStart ( I2cMasterContext,
+      Status = MvI2cStart (I2cMasterContext,
                    (SlaveAddress << 1) | ReadMode,
                    I2C_TRANSFER_TIMEOUT
                  );
     } else if (!(Operation->Flags & I2C_FLAG_NORESTART)) {
-      MvI2cRepeatedStart ( I2cMasterContext,
+      Status = MvI2cRepeatedStart (I2cMasterContext,
                            (SlaveAddress << 1) | ReadMode,
                            I2C_TRANSFER_TIMEOUT
                          );
     }
 
+    /* I2C transaction was aborted, so stop further transactions */
+    if (EFI_ERROR (Status)) {
+      MvI2cStop (I2cMasterContext);
+      break;
+    }
+
+    /*
+     * If sending the slave address was successful,
+     * proceed to read or write section.
+     */
     if (ReadMode) {
-      MvI2cRead ( I2cMasterContext,
+      Status = MvI2cRead (I2cMasterContext,
                   Operation->Buffer,
                   Operation->LengthInBytes,
                   &Transmitted,
                   Count == 1,
                   I2C_TRANSFER_TIMEOUT
                  );
+      Operation->LengthInBytes = Transmitted;
     } else {
-      MvI2cWrite ( I2cMasterContext,
+      Status = MvI2cWrite (I2cMasterContext,
                    Operation->Buffer,
                    Operation->LengthInBytes,
                    &Transmitted,
                    I2C_TRANSFER_TIMEOUT
                   );
+      Operation->LengthInBytes = Transmitted;
     }
+
+    /*
+     * The I2C read or write transaction failed.
+     * Stop the I2C transaction.
+     */
+    if (EFI_ERROR (Status)) {
+      MvI2cStop (I2cMasterContext);
+      break;
+    }
+
+    /* Check if there is any more data to be sent */
     if (Count == RequestPacket->OperationCount - 1) {
-      MvI2cStop ( I2cMasterContext );
+      MvI2cStop (I2cMasterContext);
     }
   }
 
-- 
2.7.4