Linux/DRA725: Free GBM abnormal

Tool/software: Linux

hardware: DRA725 custom board
software: ti-processor-sdk-linux-automotive-dra7xx-evm-03_04_00_03

My test case is loop for create and free GBM, I expect it run continuously.
But it's failure. I already upload my test case to github.
github.com/.../gbmtest.git

TEST case 1 run success
source code:
  while (1) {
     init_gbm();
     exit_gbm();
  }
 
 
TEST case 2 run failure, second loop break for error msg:
 WSEGL_InitialiseDisplay():789|ERROR> GBM device passed 0x3d7b0 does not match with initialized value 0x25968
source code:
  while (1) {
     init_gbm();
     init_gl();
     exit_gl();
     exit_gbm();
  }
 
 
 
TEST case 3 run failure, fifth loop break for error msg:
 WSEGL_InitialiseDisplay():789|ERROR> GBM device passed 0x3ed18 does not match with initialized value 0x25968
source code:
  while (1) {
     init_gbm();
     init_gl();
     draw();
     eglSwapBuffers();
     gbm_surface_lock_front_buffer();
     gbm_surface_release_buffer();
     exit_gl();
     exit_gbm();
  }