Cleanup the MCA param registration - the MPI_T interface is allowed to modify the value, so don't read the value until we are ready to use it. Discussed with Nathan, but will ask his review prior to porting it to 1.8.2

Refs trac:4816

This commit was SVN r32379.

The following Trac tickets were found above:
  Ticket 4816 --> https://svn.open-mpi.org/trac/ompi/ticket/4816

opal/mca/btl/openib/btl_openib_component.c

@@ -1935,6 +1935,23 @@ static int init_one_device(opal_list_t *btl_list, struct ibv_device* ib_dev)
 
         */
 
+        {
+            /* we need to read this MCA param at this point in case someone
+             * altered it via MPI_T */
+            int index;
+            mca_base_var_source_t source;
+            index = mca_base_var_find("opal","btl","openib","receive_queues");
+            if (index >= 0) {
+                if (OPAL_SUCCESS != (ret = mca_base_var_get_value(index, NULL, &source, NULL))) {
+                    BTL_ERROR(("mca_base_var_get_value failed to get value for receive_queues: %s:%d", 
+                               __FILE__, __LINE__));
+                    goto error;
+                } else {
+                    mca_btl_openib_component.receive_queues_source = source;
+                }
+            }
+        }
+
         /* If the MCA param was specified, skip all the checks */
         if ( MCA_BASE_VAR_SOURCE_COMMAND_LINE ||
                 MCA_BASE_VAR_SOURCE_ENV ==

opal/mca/btl/openib/btl_openib_mca.c

@@ -222,8 +222,7 @@ int btl_openib_register_mca_params(void)
     char default_qps[100];
     uint32_t mid_qp_size;
     char *msg, *str;
-    int ret, tmp, index;
-    mca_base_var_source_t source;
+    int ret, tmp;
 
     ret = OPAL_SUCCESS;
 #define CHECK(expr) do {\
@@ -665,16 +664,6 @@ int btl_openib_register_mca_params(void)
                      default_qps, &mca_btl_openib_component.receive_queues,
                      0
                 ));
-    index = mca_base_var_find("opal","btl","openib","receive_queues");
-    if (index >= 0) {
-        if (OPAL_SUCCESS != (ret = mca_base_var_get_value(index, NULL, &source, NULL))) {
-            BTL_ERROR(("mca_base_var_get_value failed to get value for receive_queues: %s:%d", 
-                        __FILE__, __LINE__));
-            return ret;
-        } else {
-            mca_btl_openib_component.receive_queues_source = source;
-        }
-    }
 
     CHECK(reg_string("if_include", NULL,
                      "Comma-delimited list of devices/ports to be used (e.g. \"mthca0,mthca1:2\"; empty value means to use all ports found).  Mutually exclusive with btl_openib_if_exclude.",