Bug#489729: xserver-xorg-video-intel: synchronization with virtical refresh broken after suspend to ram

[Jens Thiele <karme@berlios.de>]

Sorry, i did submit this report by accident - it was not really
finished.

Additional notes:

The bug is about synchronization of OpenGL buffer swap to the "vertical
refresh" / display frame rate¹. 

The test script is for gauche (+gauche-gl module) [aptitude install
gauche-gl].

If you run the script, switch the window to fullscreen or at least
maximize it if your window manager isn't capable of doing this.

The expected result is a vertical white bar moving horizontally over the
screen. If the synchronization doesn't work instead of the single moving
bar you see more like a stair:

good:
 |
 |
 |

bad:
|
 |
  |

:-)

With my setup it works until I do a supend to ram and resume.

¹ using glutSwapBuffers
  <http://www.opengl.org/resources/libraries/glut/spec3/node21.html>