Ignore IPMI_SMS_ATN during fir data collection and remove 8k buffer

Also, only retry FIFO scoms once

Change-Id: I891efee8214fa4613f955035d07e3f2422afc5b0
CQ: SW464968
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/83490
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: William A Bryan <wilbryan@us.ibm.com>
Reviewed-by: Martha Broyles <mbroyles@us.ibm.com>
Reviewed-by: Zane C Shelley <zshelle@us.ibm.com>
Reviewed-by: Christopher J Cain <cjcain@us.ibm.com>

13 files changed, 121 insertions, 46 deletions

diff --git a/src/occ_405/occbuildname.c b/src/occ_405/occbuildname.c
index dd3747c..2d923d8 100755
--- a/src/occ_405/occbuildname.c
+++ b/src/occ_405/occbuildname.c
@@ -34,6 +34,6 @@ volatile const char G_occ_buildname[16] __attribute__((section(".buildname"))) =
 
 #else
 
-volatile const char G_occ_buildname[16] __attribute__((section(".buildname"))) = /*<BuildName>*/  "op_occ_190822a\0"  /*</BuildName>*/ ;
+volatile const char G_occ_buildname[16] __attribute__((section(".buildname"))) = /*<BuildName>*/  "op_occ_190910a\0"  /*</BuildName>*/ ;
 
 #endif
diff --git a/src/occ_gpe0/firdata/firData.c b/src/occ_gpe0/firdata/firData.c
index fc827b0..84e59d2 100644
--- a/src/occ_gpe0/firdata/firData.c
+++ b/src/occ_gpe0/firdata/firData.c
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2018                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -823,6 +823,7 @@ void FirData_addTrgtsToPnor( FirData_t * io_fd )
     uint32_t i = 0;
     for ( i = 0; i < io_fd->hData->chipCount; i++ )
     {
+        TRAC_IMP("FirData_addTrgtsToPnor: chip %d", i);
         // Keep a pointer of the current chip header.
         HOMER_Chip_t * chipHdr = (HOMER_Chip_t *) byteIdx;
         byteIdx += sizeof(HOMER_Chip_t);
diff --git a/src/occ_gpe0/firdata/fsi.c b/src/occ_gpe0/firdata/fsi.c
index 767bcf4..95021d6 100644
--- a/src/occ_gpe0/firdata/fsi.c
+++ b/src/occ_gpe0/firdata/fsi.c
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -37,6 +37,7 @@
 
 void fsi_recovery()
 {
+    TRAC_IMP(">>fsi_recovery");
     int32_t rc = SUCCESS;
 
     /* Clear out OPB error */
@@ -48,8 +49,8 @@ void fsi_recovery()
     /* Check if we have any errors left */
     rc |= xscom_read( OPB_REG_STAT, &scom_data );
 
-    TRACFCOMP( "PIB2OPB Status after cleanup = %08X%08X (rc=%d)",
-               (uint32_t)(scom_data >> 32), (uint32_t)scom_data, rc );
+    TRAC_IMP( "<<fsi_recovery: PIB2OPB Status after cleanup = %08X%08X (rc=%d)",
+              (uint32_t)(scom_data >> 32), (uint32_t)scom_data, rc );
 }
 
 /**
diff --git a/src/occ_gpe0/firdata/ipmidd.C b/src/occ_gpe0/firdata/ipmidd.C
index 69bf429..1b2130a 100644
--- a/src/occ_gpe0/firdata/ipmidd.C
+++ b/src/occ_gpe0/firdata/ipmidd.C
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/ipmidd.C $                                */
+/* $Source: src/occ_gpe0/firdata/ipmidd.C $                               */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2018                             */
+/* Contributors Listed Below - COPYRIGHT 2018,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -107,7 +107,7 @@ int IpmiDD::writeLPC(const uint32_t i_addr,
  */
 int IpmiDD::pollCtrl(void)
 {
-    IPMI_TRAC(">>pollCtrl" );
+    //IPMI_TRAC(">>pollCtrl" );
     int rc = 0;
 
     uint8_t ctrl = 0;
@@ -237,9 +237,11 @@ int IpmiDD::send(void)
             break;
         }
 
+#if 0
         IPMI_TRAC("I> write %x:%x seq %x len %x",
                   iv_netfun, iv_cmd, iv_seq,
                   iv_data_len);
+#endif
 
         // If all is well, alert the host we sent bits.
         err = writeLPC(REG_CONTROL, CTRL_H2B_ATN);
@@ -374,11 +376,13 @@ int IpmiDD::receive(void)
     }
 
 
+#if 0
     IPMI_TRAC("I> read b2h %x:%x seq %x cc %x",
               iv_netfun,
               iv_cmd,
               iv_seq,
               iv_cc);
+#endif
 
     return err;
 }
diff --git a/src/occ_gpe0/firdata/ipmidd.H b/src/occ_gpe0/firdata/ipmidd.H
index 18eebbf..bff9ec5 100644
--- a/src/occ_gpe0/firdata/ipmidd.H
+++ b/src/occ_gpe0/firdata/ipmidd.H
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/ipmidd.H $                                */
+/* $Source: src/occ_gpe0/firdata/ipmidd.H $                               */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2018                             */
+/* Contributors Listed Below - COPYRIGHT 2018,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -91,8 +91,8 @@ enum {
     CTRL_CLR_RD_PTR    = (1 << 1),
     CTRL_CLR_WR_PTR    = (1 << 0),
 
-    IDLE_STATE = (CTRL_B_BUSY | CTRL_B2H_ATN |
-                  CTRL_SMS_ATN | CTRL_H2B_ATN),
+    // Ignore CTRL_SMS_ATN
+    IDLE_STATE = (CTRL_B_BUSY | CTRL_B2H_ATN | CTRL_H2B_ATN),
 
     // Bit in the INMASK register which signals to the BMC
     // to reset it's end of things.
diff --git a/src/occ_gpe0/firdata/lpc.c b/src/occ_gpe0/firdata/lpc.c
index 3f9f113..c19c7e4 100644
--- a/src/occ_gpe0/firdata/lpc.c
+++ b/src/occ_gpe0/firdata/lpc.c
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/lpc.c $                                   */
+/* $Source: src/occ_gpe0/firdata/lpc.c $                                  */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -241,7 +241,11 @@ errorHndl_t lpc_read( LpcTransType i_type,
         /* Poll for completion */
         StatusReg_t lpc_status;
         l_err = pollComplete( &lpc_cmd, &lpc_status );
-        if( l_err ) { break; }
+        if( l_err )
+        {
+            TRAC_ERR("lpc_read: pollComplete failed rc=0x%08x", (uint32_t)l_err);
+            break;
+        }
 
         // Read data from the LPC_DATA_REG
         l_err = SCOM_getScom(l_target, LPC_DATA_REG, &l_ret);
diff --git a/src/occ_gpe0/firdata/mboxOverIpmi.C b/src/occ_gpe0/firdata/mboxOverIpmi.C
index c0ee243..d3bc313 100644
--- a/src/occ_gpe0/firdata/mboxOverIpmi.C
+++ b/src/occ_gpe0/firdata/mboxOverIpmi.C
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/mboxOverIpmi.C $                          */
+/* $Source: src/occ_gpe0/firdata/mboxOverIpmi.C $                         */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2018                             */
+/* Contributors Listed Below - COPYRIGHT 2018,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -62,11 +62,17 @@ int ipmi_sendCommand(mboxMessage_t *io_msg, int i_arg_size)
 
     do
     {
+#if 0
+        rc = l_ipmidd.pollCtrl();
+        TRAC_ERR("ipmi_sendCommand: DUMMY RECEIVE returned rc=%d", rc);
+#endif
+
         for(i = 0; i < IPMI_MAX_TRIES; ++i)
         {
             rc = l_ipmidd.send();
             if(rc != RC_IPMIDD_NOT_IDLE)
             {
+                // command was sent
                 break;
             }
             busy_wait(100); // 100 us
diff --git a/src/occ_gpe0/firdata/pnor_mboxdd.c b/src/occ_gpe0/firdata/pnor_mboxdd.c
index 4251eda..3961f7c 100644
--- a/src/occ_gpe0/firdata/pnor_mboxdd.c
+++ b/src/occ_gpe0/firdata/pnor_mboxdd.c
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/pnor_mboxdd.c $                           */
+/* $Source: src/occ_gpe0/firdata/pnor_mboxdd.c $                          */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2017                             */
+/* Contributors Listed Below - COPYRIGHT 2017,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -223,7 +223,7 @@ errorHndl_t writeFlash(pnorMbox_t* i_pnorMbox,
                 break;
             }
 
-            //LPC writes are done via LPC scom interface and can only handle 4 
+            //LPC writes are done via LPC scom interface and can only handle 4
             //bytes at a time. We write 256 bytes from the previous functions,
             // so break up the large write into 4 byte writes
             uint32_t l_size_written = 0;
diff --git a/src/occ_gpe0/firdata/pnor_util.c b/src/occ_gpe0/firdata/pnor_util.c
index fb579e2..d5b86f0 100644
--- a/src/occ_gpe0/firdata/pnor_util.c
+++ b/src/occ_gpe0/firdata/pnor_util.c
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/pnor_util.c $                             */
+/* $Source: src/occ_gpe0/firdata/pnor_util.c $                            */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2017                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -51,6 +51,14 @@ int32_t pnor_write_8B( uint64_t i_data )
 {
     int32_t rc = SUCCESS;
 
+    // ensure current index is within range
+    if (g_write_cache_index > PAGE_PROGRAM_BYTES)
+    {
+        TRAC_ERR("pnor_write_8B: ERROR - g_write_cache_index > PAGE_PROGRAM_BYTES!");
+        g_write_cache_index = 0;
+        g_next_byte = 0xFFFFFFFF;
+    }
+
     if ( (g_next_byte == 0xFFFFFFFF) || /* initialized data */
          ((g_next_byte + g_pnor_size) < (g_next_byte + 9)) ) /* make sure there is room */
     {
@@ -92,7 +100,7 @@ int32_t pnor_write_8B( uint64_t i_data )
                                       g_write_cache );
         if ( NO_ERROR != tmp )
         {
-            TRACFCOMP("pnor_write_8B> writeFlash failed");
+            TRAC_IMP("pnor_write_8B> writeFlash failed");
             /* hit an error, stop any more writes from happening */
             g_next_byte = 0xFFFFFFFF;
             g_pnor_size = 0;
@@ -171,6 +179,7 @@ int32_t PNOR_writeFirData( HOMER_PnorInfo_t i_pnorInfo,
         uint64_t dataChunk  = 0;
         uint32_t sz_dataChunk = sizeof(uint64_t);
 
+        TRAC_IMP("PNOR_writeFirData: writing %d bytes (%d byte chunks)", i_bufSize, sz_dataChunk);
         /* Add PNOR data 8 bytes at a time. */
         for ( idx = 0; idx < i_bufSize; idx += sz_dataChunk )
         {
@@ -180,7 +189,7 @@ int32_t PNOR_writeFirData( HOMER_PnorInfo_t i_pnorInfo,
             rc = pnor_write_8B( dataChunk );
             if ( SUCCESS != rc )
             {
-                TRACFCOMP( "pnor_write_8B() failed during FIR write" );
+                TRAC_ERR( "pnor_write_8B() failed during FIR write" );
                 break;
             }
         }
@@ -201,7 +210,7 @@ int32_t PNOR_writeFirData( HOMER_PnorInfo_t i_pnorInfo,
             rc = pnor_write_8B( dataChunk );
             if ( SUCCESS != rc )
             {
-                TRACFCOMP( "pnor_write_8B() failed during blank fill" );
+                TRAC_ERR( "pnor_write_8B() failed during blank fill" );
                 break;
             }
         }
@@ -215,14 +224,14 @@ int32_t PNOR_writeFirData( HOMER_PnorInfo_t i_pnorInfo,
             rc = pnor_write_8B( dataChunk );
             if ( SUCCESS != rc )
             {
-                TRACFCOMP( "pnor_write_8B() failed during ECC fill" );
+                TRAC_ERR( "pnor_write_8B() failed during ECC fill" );
                 break;
             }
         }
 
     } while (0);
 
-    TRACFCOMP("<<PNOR_writeFirData");
+    TRAC_IMP("<<PNOR_writeFirData returning %d", rc);
     return rc;
 }
 
diff --git a/src/occ_gpe0/firdata/sbe_fifo.c b/src/occ_gpe0/firdata/sbe_fifo.c
index 4f0bd2f..f3eb0bf 100644
--- a/src/occ_gpe0/firdata/sbe_fifo.c
+++ b/src/occ_gpe0/firdata/sbe_fifo.c
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/sbe_fifo.c $                              */
+/* $Source: src/occ_gpe0/firdata/sbe_fifo.c $                             */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2017                             */
+/* Contributors Listed Below - COPYRIGHT 2017,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -159,6 +159,7 @@ uint32_t upFifoReset(SCOM_Trgt_t* i_target)
             l_rc = getfsi(i_target, l_addr, &l_data);
             if(l_rc != SUCCESS)
             {
+                TRAC_ERR("upFifoReset:getfsi(0x%08X) failed. rc = %d", l_addr, l_rc);
                 break;
             }
 
@@ -200,7 +201,7 @@ uint32_t writeRequest(SCOM_Trgt_t* i_target, uint32_t* i_fifoRequest)
     l_rc = putfsi(i_target, l_addr, l_data);
     if(l_rc != SUCCESS)
     {
-        TRAC_ERR("writeRequest: failed to putfsi to addr 0x%08x",
+        TRAC_ERR("<<writeRequest: failed to putfsi to addr 0x%08x",
                  l_addr);
         return l_rc;
     }
@@ -217,6 +218,7 @@ uint32_t writeRequest(SCOM_Trgt_t* i_target, uint32_t* i_fifoRequest)
         l_rc = waitUpFifoReady(i_target);
         if(l_rc != SUCCESS)
         {
+            TRAC_ERR("<<writeRequest waitUpFifoReady[%d] rc=%d", i, l_rc);
             return l_rc;
         }
 
@@ -224,8 +226,8 @@ uint32_t writeRequest(SCOM_Trgt_t* i_target, uint32_t* i_fifoRequest)
         l_rc = putfsi(i_target, l_addr, *l_sent);
         if(l_rc != SUCCESS)
         {
-            TRAC_ERR("writeRequest: failed to putfsi to addr 0x%08x",
-                     l_addr);
+            TRAC_ERR("<<writeRequest: failed to putfsi[%d] to addr 0x%08x",
+                     i, l_addr);
             return l_rc;
         }
 
@@ -236,6 +238,7 @@ uint32_t writeRequest(SCOM_Trgt_t* i_target, uint32_t* i_fifoRequest)
     l_rc = waitUpFifoReady(i_target);
     if(l_rc != SUCCESS)
     {
+        TRAC_ERR("<<writeRequest waitUpFifoReady rc=%d", l_rc);
         return l_rc;
     }
 
@@ -244,7 +247,7 @@ uint32_t writeRequest(SCOM_Trgt_t* i_target, uint32_t* i_fifoRequest)
     l_rc = putfsi(i_target, l_addr, l_data);
     if(l_rc != SUCCESS)
     {
-        TRAC_ERR("writeRequest: failed to putfsi to addr 0x%08x", l_addr);
+        TRAC_ERR("<<writeRequest: failed to putfsi to addr 0x%08x, rc=%d", l_addr, l_rc);
     }
 
     return l_rc;
@@ -293,6 +296,21 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
 
     memset( o_responseData, 0, sizeof(uint64_t) ); // Just in case.
 
+    // NORMAL RESPONSE:
+    //
+    // 0: SCOM_WORD_0
+    // 1: SCOM_WORD_1
+    // 2: 0: RespStatus.magic
+    //    2: RespStatus.command.class
+    //    3: RespStatus.command.type
+    // 3: 0: RespStatus.primaryStatus
+    //    2: RespStatus.secondaryStatus
+    // 4: DISTANCE
+    // 5: EOT (ignored - does not need to be stored in buffer)
+    //
+    // If there is a scom error, FFDC may get returned which would be larger than
+    // the normal expected 5 words which would result in RC_RESP_DATA_OVERFLOW
+
     uint32_t readBuffer[READ_BUFFER_SIZE];
     uint32_t wordsReceived = 0;
 
@@ -303,6 +321,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
         l_rc = waitDnFifoReady( i_target, &l_status );
         if ( SUCCESS != l_rc )
         {
+            TRAC_ERR("readResponse: waitDnFifoReady failed, rc=%d, status=%d", l_rc, l_status);
             return l_rc;
         }
 
@@ -321,7 +340,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
         {
             TRAC_ERR( "readResponse: data overflow without EOT. "
                       "wordsReceived=%u", wordsReceived );
-            printBuffer( readBuffer, wordsReceived );
+            //printBuffer( readBuffer, wordsReceived );
             return RC_RESP_DATA_OVERFLOW;
         }
 
@@ -354,7 +373,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
     {
         TRAC_ERR( "readResponse: minimum response size is invalid. "
                   "wordsReceived=%u", wordsReceived );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_MIN_SIZE_INVALID;
     }
 
@@ -365,7 +384,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
     {
         TRAC_ERR( "readResponse: invalid response distance. wordsReceived=%u "
                   "distance=%u", wordsReceived, distance );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_DISTANCE_INVALID;
     }
 
@@ -377,7 +396,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
     {
         TRAC_ERR( "readResponse: invalid magic word. magic=0x%04x",
                   status->magic );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_MAGIC_WORD_INVALID;
     }
 
@@ -386,7 +405,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
     {
         TRAC_ERR( "readResponse: unexpected response command. cmd=0x%08x",
                   status->command.u );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_UNEXPECTED_CMD;
     }
 
@@ -414,7 +433,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
                   "primaryStatus=0x%08x secondaryStatus=0x%08x",
                   i_fifoReqCmd->u, status->primaryStatus,
                   status->secondaryStatus );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_SCOM_ERROR;
     }
 
@@ -425,7 +444,7 @@ uint32_t readResponse( SCOM_Trgt_t* i_target, FifoCmd_t* i_fifoReqCmd,
         TRAC_ERR( "readResponse: unexpected response data size. cmd=0x%08x "
                   "wordsReceived=%u distance=%u", i_fifoReqCmd->u,
                   wordsReceived, distance );
-        printBuffer( readBuffer, wordsReceived );
+        //printBuffer( readBuffer, wordsReceived );
         return RC_RESP_UNEXPECTED_DATA_SIZE;
     }
 
@@ -475,6 +494,7 @@ int32_t putFifoScom(SCOM_Trgt_t* i_target, uint64_t i_addr, uint64_t i_data)
 int32_t getFifoScom(SCOM_Trgt_t* i_target, uint64_t i_addr, uint64_t* o_data)
 {
     uint32_t l_rc = SUCCESS;
+    unsigned int l_cmd_attempts = 0;
 
     struct fifoGetScomRequest  l_fifoRequest;
     l_fifoRequest.wordCnt = GET_SCOM_REQUEST_WORD_CNT;
@@ -482,6 +502,7 @@ int32_t getFifoScom(SCOM_Trgt_t* i_target, uint64_t i_addr, uint64_t* o_data)
     l_fifoRequest.command.s.class = SBE_FIFO_CLASS_SCOM_ACCESS;
     l_fifoRequest.command.s.type  = SBE_FIFO_CMD_GET_SCOM;
     l_fifoRequest.address = i_addr;
+    static unsigned int L_throttle_trace = 0;
 
     do
     {
@@ -506,8 +527,15 @@ int32_t getFifoScom(SCOM_Trgt_t* i_target, uint64_t i_addr, uint64_t* o_data)
             break;
         }
 
+        ++l_cmd_attempts;
         if ( l_rc != SUCCESS )
         {
+            if (L_throttle_trace < 5)
+            {
+                TRAC_ERR("getFifoScom: readResponse(0x%08X) try #%d failed with %d...  Calling upFifoReset() #%d",
+                         i_addr, l_cmd_attempts, l_rc, L_throttle_trace);
+            }
+
             // Reset the FIFO for subsequent SCOMs
             uint32_t resetRc = upFifoReset(i_target);
             if(resetRc == RC_FIFO_TIMEOUT_RESET)
@@ -515,6 +543,17 @@ int32_t getFifoScom(SCOM_Trgt_t* i_target, uint64_t i_addr, uint64_t* o_data)
                 // timeout msg already traced, Return original fail rc.
                 break;
             }
+
+            if (l_cmd_attempts >= 2)
+            {
+                if (L_throttle_trace < 5)
+                {
+                    ++L_throttle_trace;
+                    TRAC_ERR("getFifoScom: returning FIFO_TIMEOUT_DN (skipping additional retries)");
+                }
+                l_rc = RC_FIFO_TIMEOUT_DN;
+                break;
+            }
         }
 
     } while ( TRUE );
diff --git a/src/occ_gpe0/firdata/sbe_fifo.h b/src/occ_gpe0/firdata/sbe_fifo.h
index 7b6df51..1464700 100644
--- a/src/occ_gpe0/firdata/sbe_fifo.h
+++ b/src/occ_gpe0/firdata/sbe_fifo.h
@@ -1,11 +1,11 @@
 /* IBM_PROLOG_BEGIN_TAG                                                   */
 /* This is an automatically generated prolog.                             */
 /*                                                                        */
-/* $Source: src/occ_405/firdata/sbe_fifo.h $                              */
+/* $Source: src/occ_gpe0/firdata/sbe_fifo.h $                             */
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2017                             */
+/* Contributors Listed Below - COPYRIGHT 2017,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -51,7 +51,9 @@
 #define SBE_FIFO_DNFIFO_DATA_OUT 0x00002440
 #define NS_PER_MSEC (1000000ull)
 #define MAX_UP_FIFO_TIMEOUT_NS 10*NS_PER_MSEC
-#define READ_BUFFER_SIZE 2048
+// READ_BUFFER_SIZE is number of words when reading scom via SBE
+// (2 words of scom data + 3 words of header)
+#define READ_BUFFER_SIZE 5
 #define FIFO_STATUS_MAGIC 0xC0DE
 #define SBE_PRI_OPERATION_SUCCESSFUL 0x00
 #define SBE_SEC_OPERATION_SUCCESSFUL 0x00
diff --git a/src/occ_gpe0/firdata/scom_trgt.c b/src/occ_gpe0/firdata/scom_trgt.c
index 9eae5a7..4671581 100644
--- a/src/occ_gpe0/firdata/scom_trgt.c
+++ b/src/occ_gpe0/firdata/scom_trgt.c
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2018                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
diff --git a/src/occ_gpe0/firdata/scom_util.c b/src/occ_gpe0/firdata/scom_util.c
index 0102477..3fdc9de 100644
--- a/src/occ_gpe0/firdata/scom_util.c
+++ b/src/occ_gpe0/firdata/scom_util.c
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER OnChipController Project                                     */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2015,2018                        */
+/* Contributors Listed Below - COPYRIGHT 2015,2019                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -396,6 +396,11 @@ int32_t SCOM_getScom( SCOM_Trgt_t i_trgt, uint32_t i_addr, uint64_t * o_val )
         }
     }
 
+    if (rc != SUCCESS)
+    {
+        TRAC_ERR("SCOM_getScom(0x%08X): returning %d", i_addr, rc);
+    }
+
     return rc;
 }
 
@@ -466,7 +471,11 @@ int32_t SCOM_getIdScom( SCOM_Trgt_t i_trgt, uint64_t i_addr, uint32_t * o_val )
         {
             rc = getscom_abs(trans_addr, &(scomout.data64));
         }
-        if ( SUCCESS != rc ) return rc;
+        if ( SUCCESS != rc )
+        {
+            TRAC_ERR("SCOM_getIdScom(0x%08X): returning %d", i_addr, rc);
+            return rc;
+        }
 
         /* Check for PIB error. */
         if ( scomout.piberr )