Hi, everyone , I have a trouble when config graphics.conf. the screen failed to startup when config the following 
parmaters in graphics.conf:
   gpu-pm-enable = true
   gpu-pm-force-power-on = false
   gpu-powerManagement = 1

and sloginfo show the following error logs:
 gckGALDEVICE_Start_Threads(1442): wrong setting of gpu-heartbeat-interval (0) in graphics.conf
Dec 31 19:14:49    2     8   100  [gckOS_MemoryBarrier] device io map for PL310 L2 Cache controller is Failed or not-
done (abort ... )

Can someone help me? Thanks!