This MIGHT work !

<OLD PRIMARY> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;

If successful then shutdown and startup

ELSE

When the switchover to change the role from primary to physical standby was

initiated, a trace file was written in the log directory. This trace file contains the

SQL statements required to re-create the original primary control file. Locate the

trace file and extract the SQL statements into a temporary file. Execute the

temporary file from SQL*Plus. This will revert the new standby database back to

the primary role.

3. shutdown original standby

4. Create a new standby control file. This is necessary to resynchronize the primary

database and physical standby database. Copy the physical standby control file to

the original physical standby system. Section 3.2.2 describes how to create a

physical standby control file.

5. Restart the original physical standby instance.

If this procedure is successful and archive gap management is enabled, the FAL

processes will start and re-archive any missing archived redo log files to the

physical standby database. Force a log switch on the primary database and

examine the alert logs on both the primary database and physical standby

database to ensure the archived redo log file sequence numbers are correct.

See Section 5.8 for information about archive gap management and Appendix G

for information about locating the trace files.

6. Try the switchover again.

At this point, the Data Guard configuration has been rolled back to its initial state,

and you can try the switchover operation again (after correcting any problems that

might have led to the initial unsuccessful switchover).