Don't clear SGPE/PGPE OCC flags until after the engines are halted

Change-Id: Id707a12d3e7dd00c310a01630a2e520b2ed22a6e
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/46873
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Gregory S. Still <stillgs@us.ibm.com>
Reviewed-by: Juan R. Medina <jrmedina@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/46878
Reviewed-by: Hostboot Team <hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/import/chips/p9/procedures/hwp/pm/p9_pm_reset.C

@@ -95,15 +95,6 @@ fapi2::ReturnCode p9_pm_reset(
     FAPI_TRY(l_rc, "ERROR: Failed to mask OCC FIRs.");
     FAPI_TRY(p9_pm_glob_fir_trace(i_target, "After masking FIRs"));
 
-    // Clear the OCC Flag and Scratch2 registers
-    // which contain runtime settings and modes for PM GPEs (Pstate and Stop functions)
-    l_data64.flush<0>();
-    FAPI_TRY(fapi2::putScom(i_target, PU_OCB_OCI_OCCFLG_SCOM, l_data64),
-             "ERROR: Failed to write to OCC Flag Register");
-
-    FAPI_TRY(fapi2::putScom(i_target, PU_OCB_OCI_OCCS2_SCOM, l_data64),
-             "ERROR: Failed to write to OCC Scratch2 Register");
-
     //  ************************************************************************
     //  Halt the OCC PPC405 and reset it safely
     //  ************************************************************************
@@ -161,6 +152,17 @@ fapi2::ReturnCode p9_pm_reset(
     FAPI_TRY(l_rc, "ERROR: Failed to reset SGPE");
     FAPI_TRY(p9_pm_glob_fir_trace(i_target, "After reset of SGPE"));
 
+    //  ************************************************************************
+    // Clear the OCC Flag and Scratch2 registers
+    // which contain runtime settings and modes for PM GPEs (Pstate and Stop functions)
+    //  ************************************************************************
+    l_data64.flush<0>();
+    FAPI_TRY(fapi2::putScom(i_target, PU_OCB_OCI_OCCFLG_SCOM, l_data64),
+             "ERROR: Failed to write to OCC Flag Register");
+    FAPI_TRY(fapi2::putScom(i_target, PU_OCB_OCI_OCCS2_SCOM, l_data64),
+             "ERROR: Failed to write to OCC Scratch2 Register");
+
+
     //  ************************************************************************
     //  Reset Cores and Quads
     //  ************************************************************************