Following ScaLAPACK routines change BLACS topology and invoke PB_TOPGET instead of PB_TOPSET to restore topology: pdorgql psorml2 pcungql pzungql pdorml2 pcungqr pcunml2 psorgqr pzunml2 pdorgqr psorgql pzungqr.
This may lead to error in some cases, particularly in following scenario:
1) run ScaLAPACK routine which changes topology on 2 MPI processes, remaining 2 MPI processes are used for some other calculations
2) redefine BLACS grid expecting all is OK now; however BLACS topology settings are defined as static variables
4) run ScaLAPACK/BLACS routine which use topology settings (pzgemm for example); get an error as topology settings are invalid (not the same for all MPI processes in the grid)