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Black rendering of windowed Open GLES applications on iMX6 Vivante under X11

Question asked by DiegoFSL on Jul 23, 2013
Latest reply on Oct 17, 2013 by Peter Suciu

Hi everybody.


I'm experiencing a very strange issue with Vivante driver on i.MX6 platform (Boundary Nitrogen6X).


I've experienced that these assertions are always true with the tests I've made:

  1. OpenGL ES applications render correctly in windowed mode as long as "unity-2d-launcher" process is running;
  2. OpenGL ES applications render solid black in windowed mode as long as "unity-2d-launcher" process is not running.


This holds true even if you change the window manager (I've tested metacity with compiz, openbox and xfwm4). For example if you start the process "unity-2d-launcher" under an openbox session you get correct rendering; if you kill "unity-2d-launcher" you get black rendering.

This holds true even changing OS: it's valid under both Freescale Ubuntu BSP 4.0.0 and Yocto with BSP 4.0.0. Obviously only the second part (black rendering) is verifiable under Yocto, as Unity2D is available only in Ubuntu.


Unity2D Launcher depends on some runtime libraries. I thought that there were some weird dependencies in the Unity2D Launcher libraries chain; however, if you load in memory the entire library dependency-chain but not the final Unity2D Launcher binary, and if you render a scene
in a window (using for example glmark2-es2, a popular benchmark tool), the window is black. If I finally load the Unity2D Launcher binary the windowed rendering works.


How is possible that a such component (Unity2D Launcher) influences the rendering of a scene in a X11 environment?

This bug prevent using other desktop environment to render OpenGL ES scenes in a window.